1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2015, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Aspects; use Aspects;
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Einfo; use Einfo;
30 with Elists; use Elists;
31 with Exp_Atag; use Exp_Atag;
32 with Exp_Ch2; use Exp_Ch2;
33 with Exp_Ch3; use Exp_Ch3;
34 with Exp_Ch6; use Exp_Ch6;
35 with Exp_Ch9; use Exp_Ch9;
36 with Exp_Dist; use Exp_Dist;
37 with Exp_Imgv; use Exp_Imgv;
38 with Exp_Pakd; use Exp_Pakd;
39 with Exp_Strm; use Exp_Strm;
40 with Exp_Tss; use Exp_Tss;
41 with Exp_Util; use Exp_Util;
42 with Fname; use Fname;
43 with Freeze; use Freeze;
44 with Gnatvsn; use Gnatvsn;
45 with Itypes; use Itypes;
47 with Namet; use Namet;
48 with Nmake; use Nmake;
49 with Nlists; use Nlists;
51 with Restrict; use Restrict;
52 with Rident; use Rident;
53 with Rtsfind; use Rtsfind;
55 with Sem_Aux; use Sem_Aux;
56 with Sem_Ch6; use Sem_Ch6;
57 with Sem_Ch7; use Sem_Ch7;
58 with Sem_Ch8; use Sem_Ch8;
59 with Sem_Eval; use Sem_Eval;
60 with Sem_Res; use Sem_Res;
61 with Sem_Util; use Sem_Util;
62 with Sinfo; use Sinfo;
63 with Snames; use Snames;
64 with Stand; use Stand;
65 with Stringt; use Stringt;
66 with Targparm; use Targparm;
67 with Tbuild; use Tbuild;
68 with Ttypes; use Ttypes;
69 with Uintp; use Uintp;
70 with Uname; use Uname;
71 with Validsw; use Validsw;
73 package body Exp_Attr is
75 -----------------------
76 -- Local Subprograms --
77 -----------------------
79 function Build_Array_VS_Func
81 Nod : Node_Id) return Entity_Id;
82 -- Build function to test Valid_Scalars for array type A_Type. Nod is the
83 -- Valid_Scalars attribute node, used to insert the function body, and the
84 -- value returned is the entity of the constructed function body. We do not
85 -- bother to generate a separate spec for this subprogram.
87 function Build_Record_VS_Func
89 Nod : Node_Id) return Entity_Id;
90 -- Build function to test Valid_Scalars for record type A_Type. Nod is the
91 -- Valid_Scalars attribute node, used to insert the function body, and the
92 -- value returned is the entity of the constructed function body. We do not
93 -- bother to generate a separate spec for this subprogram.
95 procedure Compile_Stream_Body_In_Scope
100 -- The body for a stream subprogram may be generated outside of the scope
101 -- of the type. If the type is fully private, it may depend on the full
102 -- view of other types (e.g. indexes) that are currently private as well.
103 -- We install the declarations of the package in which the type is declared
104 -- before compiling the body in what is its proper environment. The Check
105 -- parameter indicates if checks are to be suppressed for the stream body.
106 -- We suppress checks for array/record reads, since the rule is that these
107 -- are like assignments, out of range values due to uninitialized storage,
108 -- or other invalid values do NOT cause a Constraint_Error to be raised.
109 -- If we are within an instance body all visibility has been established
110 -- already and there is no need to install the package.
112 -- This mechanism is now extended to the component types of the array type,
113 -- when the component type is not in scope and is private, to handle
114 -- properly the case when the full view has defaulted discriminants.
116 -- This special processing is ultimately caused by the fact that the
117 -- compiler lacks a well-defined phase when full views are visible
118 -- everywhere. Having such a separate pass would remove much of the
119 -- special-case code that shuffles partial and full views in the middle
120 -- of semantic analysis and expansion.
122 procedure Expand_Access_To_Protected_Op
126 -- An attribute reference to a protected subprogram is transformed into
127 -- a pair of pointers: one to the object, and one to the operations.
128 -- This expansion is performed for 'Access and for 'Unrestricted_Access.
130 procedure Expand_Fpt_Attribute
135 -- This procedure expands a call to a floating-point attribute function.
136 -- N is the attribute reference node, and Args is a list of arguments to
137 -- be passed to the function call. Pkg identifies the package containing
138 -- the appropriate instantiation of System.Fat_Gen. Float arguments in Args
139 -- have already been converted to the floating-point type for which Pkg was
140 -- instantiated. The Nam argument is the relevant attribute processing
141 -- routine to be called. This is the same as the attribute name, except in
142 -- the Unaligned_Valid case.
144 procedure Expand_Fpt_Attribute_R (N : Node_Id);
145 -- This procedure expands a call to a floating-point attribute function
146 -- that takes a single floating-point argument. The function to be called
147 -- is always the same as the attribute name.
149 procedure Expand_Fpt_Attribute_RI (N : Node_Id);
150 -- This procedure expands a call to a floating-point attribute function
151 -- that takes one floating-point argument and one integer argument. The
152 -- function to be called is always the same as the attribute name.
154 procedure Expand_Fpt_Attribute_RR (N : Node_Id);
155 -- This procedure expands a call to a floating-point attribute function
156 -- that takes two floating-point arguments. The function to be called
157 -- is always the same as the attribute name.
159 procedure Expand_Loop_Entry_Attribute (N : Node_Id);
160 -- Handle the expansion of attribute 'Loop_Entry. As a result, the related
161 -- loop may be converted into a conditional block. See body for details.
163 procedure Expand_Min_Max_Attribute (N : Node_Id);
164 -- Handle the expansion of attributes 'Max and 'Min, including expanding
165 -- then out if we are in Modify_Tree_For_C mode.
167 procedure Expand_Pred_Succ_Attribute (N : Node_Id);
168 -- Handles expansion of Pred or Succ attributes for case of non-real
169 -- operand with overflow checking required.
171 procedure Expand_Update_Attribute (N : Node_Id);
172 -- Handle the expansion of attribute Update
174 function Get_Index_Subtype (N : Node_Id) return Entity_Id;
175 -- Used for Last, Last, and Length, when the prefix is an array type.
176 -- Obtains the corresponding index subtype.
178 procedure Find_Fat_Info
180 Fat_Type : out Entity_Id;
181 Fat_Pkg : out RE_Id);
182 -- Given a floating-point type T, identifies the package containing the
183 -- attributes for this type (returned in Fat_Pkg), and the corresponding
184 -- type for which this package was instantiated from Fat_Gen. Error if T
185 -- is not a floating-point type.
187 function Find_Stream_Subprogram
189 Nam : TSS_Name_Type) return Entity_Id;
190 -- Returns the stream-oriented subprogram attribute for Typ. For tagged
191 -- types, the corresponding primitive operation is looked up, else the
192 -- appropriate TSS from the type itself, or from its closest ancestor
193 -- defining it, is returned. In both cases, inheritance of representation
194 -- aspects is thus taken into account.
196 function Full_Base (T : Entity_Id) return Entity_Id;
197 -- The stream functions need to examine the underlying representation of
198 -- composite types. In some cases T may be non-private but its base type
199 -- is, in which case the function returns the corresponding full view.
201 function Get_Stream_Convert_Pragma (T : Entity_Id) return Node_Id;
202 -- Given a type, find a corresponding stream convert pragma that applies to
203 -- the implementation base type of this type (Typ). If found, return the
204 -- pragma node, otherwise return Empty if no pragma is found.
206 function Is_Constrained_Packed_Array (Typ : Entity_Id) return Boolean;
207 -- Utility for array attributes, returns true on packed constrained
208 -- arrays, and on access to same.
210 function Is_Inline_Floating_Point_Attribute (N : Node_Id) return Boolean;
211 -- Returns true iff the given node refers to an attribute call that
212 -- can be expanded directly by the back end and does not need front end
213 -- expansion. Typically used for rounding and truncation attributes that
214 -- appear directly inside a conversion to integer.
216 -------------------------
217 -- Build_Array_VS_Func --
218 -------------------------
220 function Build_Array_VS_Func
222 Nod : Node_Id) return Entity_Id
224 Loc : constant Source_Ptr := Sloc (Nod);
225 Func_Id : constant Entity_Id := Make_Temporary (Loc, 'V');
226 Comp_Type : constant Entity_Id := Component_Type (A_Type);
227 Body_Stmts : List_Id;
228 Index_List : List_Id;
231 function Test_Component return List_Id;
232 -- Create one statement to test validity of one component designated by
233 -- a full set of indexes. Returns statement list containing test.
235 function Test_One_Dimension (N : Int) return List_Id;
236 -- Create loop to test one dimension of the array. The single statement
237 -- in the loop body tests the inner dimensions if any, or else the
238 -- single component. Note that this procedure is called recursively,
239 -- with N being the dimension to be initialized. A call with N greater
240 -- than the number of dimensions simply generates the component test,
241 -- terminating the recursion. Returns statement list containing tests.
247 function Test_Component return List_Id is
253 Make_Indexed_Component (Loc,
254 Prefix => Make_Identifier (Loc, Name_uA),
255 Expressions => Index_List);
257 if Is_Scalar_Type (Comp_Type) then
260 Anam := Name_Valid_Scalars;
264 Make_If_Statement (Loc,
268 Make_Attribute_Reference (Loc,
269 Attribute_Name => Anam,
271 Then_Statements => New_List (
272 Make_Simple_Return_Statement (Loc,
273 Expression => New_Occurrence_Of (Standard_False, Loc)))));
276 ------------------------
277 -- Test_One_Dimension --
278 ------------------------
280 function Test_One_Dimension (N : Int) return List_Id is
284 -- If all dimensions dealt with, we simply test the component
286 if N > Number_Dimensions (A_Type) then
287 return Test_Component;
289 -- Here we generate the required loop
293 Make_Defining_Identifier (Loc, New_External_Name ('J', N));
295 Append (New_Occurrence_Of (Index, Loc), Index_List);
298 Make_Implicit_Loop_Statement (Nod,
301 Make_Iteration_Scheme (Loc,
302 Loop_Parameter_Specification =>
303 Make_Loop_Parameter_Specification (Loc,
304 Defining_Identifier => Index,
305 Discrete_Subtype_Definition =>
306 Make_Attribute_Reference (Loc,
307 Prefix => Make_Identifier (Loc, Name_uA),
308 Attribute_Name => Name_Range,
309 Expressions => New_List (
310 Make_Integer_Literal (Loc, N))))),
311 Statements => Test_One_Dimension (N + 1)),
312 Make_Simple_Return_Statement (Loc,
313 Expression => New_Occurrence_Of (Standard_True, Loc)));
315 end Test_One_Dimension;
317 -- Start of processing for Build_Array_VS_Func
320 Index_List := New_List;
321 Body_Stmts := Test_One_Dimension (1);
323 -- Parameter is always (A : A_Typ)
325 Formals := New_List (
326 Make_Parameter_Specification (Loc,
327 Defining_Identifier => Make_Defining_Identifier (Loc, Name_uA),
329 Out_Present => False,
330 Parameter_Type => New_Occurrence_Of (A_Type, Loc)));
334 Set_Ekind (Func_Id, E_Function);
335 Set_Is_Internal (Func_Id);
338 Make_Subprogram_Body (Loc,
340 Make_Function_Specification (Loc,
341 Defining_Unit_Name => Func_Id,
342 Parameter_Specifications => Formals,
344 New_Occurrence_Of (Standard_Boolean, Loc)),
345 Declarations => New_List,
346 Handled_Statement_Sequence =>
347 Make_Handled_Sequence_Of_Statements (Loc,
348 Statements => Body_Stmts)));
350 if not Debug_Generated_Code then
351 Set_Debug_Info_Off (Func_Id);
354 Set_Is_Pure (Func_Id);
356 end Build_Array_VS_Func;
358 --------------------------
359 -- Build_Record_VS_Func --
360 --------------------------
364 -- function _Valid_Scalars (X : T) return Boolean is
366 -- -- Check discriminants
368 -- if not X.D1'Valid_Scalars or else
369 -- not X.D2'Valid_Scalars or else
375 -- -- Check components
377 -- if not X.C1'Valid_Scalars or else
378 -- not X.C2'Valid_Scalars or else
384 -- -- Check variant part
388 -- if not X.C2'Valid_Scalars or else
389 -- not X.C3'Valid_Scalars or else
396 -- if not X.Cn'Valid_Scalars or else
404 -- end _Valid_Scalars;
406 function Build_Record_VS_Func
408 Nod : Node_Id) return Entity_Id
410 Loc : constant Source_Ptr := Sloc (R_Type);
411 Func_Id : constant Entity_Id := Make_Temporary (Loc, 'V');
412 X : constant Entity_Id := Make_Defining_Identifier (Loc, Name_X);
414 function Make_VS_Case
417 Discrs : Elist_Id := New_Elmt_List) return List_Id;
418 -- Building block for variant valid scalars. Given a Component_List node
419 -- CL, it generates an 'if' followed by a 'case' statement that compares
420 -- all components of local temporaries named X and Y (that are declared
421 -- as formals at some upper level). E provides the Sloc to be used for
422 -- the generated code.
426 L : List_Id) return Node_Id;
427 -- Building block for variant validate scalars. Given the list, L, of
428 -- components (or discriminants) L, it generates a return statement that
429 -- compares all components of local temporaries named X and Y (that are
430 -- declared as formals at some upper level). E provides the Sloc to be
431 -- used for the generated code.
437 -- <Make_VS_If on shared components>
440 -- when V1 => <Make_VS_Case> on subcomponents
442 -- when Vn => <Make_VS_Case> on subcomponents
445 function Make_VS_Case
448 Discrs : Elist_Id := New_Elmt_List) return List_Id
450 Loc : constant Source_Ptr := Sloc (E);
451 Result : constant List_Id := New_List;
456 Append_To (Result, Make_VS_If (E, Component_Items (CL)));
458 if No (Variant_Part (CL)) then
462 Variant := First_Non_Pragma (Variants (Variant_Part (CL)));
468 Alt_List := New_List;
469 while Present (Variant) loop
471 Make_Case_Statement_Alternative (Loc,
472 Discrete_Choices => New_Copy_List (Discrete_Choices (Variant)),
474 Make_VS_Case (E, Component_List (Variant), Discrs)));
475 Next_Non_Pragma (Variant);
479 Make_Case_Statement (Loc,
481 Make_Selected_Component (Loc,
482 Prefix => Make_Identifier (Loc, Name_X),
483 Selector_Name => New_Copy (Name (Variant_Part (CL)))),
484 Alternatives => Alt_List));
496 -- not X.C1'Valid_Scalars
498 -- not X.C2'Valid_Scalars
504 -- or a null statement if the list L is empty
508 L : List_Id) return Node_Id
510 Loc : constant Source_Ptr := Sloc (E);
513 Field_Name : Name_Id;
518 return Make_Null_Statement (Loc);
523 C := First_Non_Pragma (L);
524 while Present (C) loop
525 Def_Id := Defining_Identifier (C);
526 Field_Name := Chars (Def_Id);
528 -- The tags need not be checked since they will always be valid
530 -- Note also that in the following, we use Make_Identifier for
531 -- the component names. Use of New_Occurrence_Of to identify
532 -- the components would be incorrect because wrong entities for
533 -- discriminants could be picked up in the private type case.
535 -- Don't bother with abstract parent in interface case
537 if Field_Name = Name_uParent
538 and then Is_Interface (Etype (Def_Id))
542 -- Don't bother with tag, always valid, and not scalar anyway
544 elsif Field_Name = Name_uTag then
547 -- Don't bother with component with no scalar components
549 elsif not Scalar_Part_Present (Etype (Def_Id)) then
552 -- Normal case, generate Valid_Scalars attribute reference
555 Evolve_Or_Else (Cond,
558 Make_Attribute_Reference (Loc,
560 Make_Selected_Component (Loc,
562 Make_Identifier (Loc, Name_X),
564 Make_Identifier (Loc, Field_Name)),
565 Attribute_Name => Name_Valid_Scalars)));
572 return Make_Null_Statement (Loc);
576 Make_Implicit_If_Statement (E,
578 Then_Statements => New_List (
579 Make_Simple_Return_Statement (Loc,
581 New_Occurrence_Of (Standard_False, Loc))));
586 -- Local Declarations
588 Def : constant Node_Id := Parent (R_Type);
589 Comps : constant Node_Id := Component_List (Type_Definition (Def));
590 Stmts : constant List_Id := New_List;
591 Pspecs : constant List_Id := New_List;
595 Make_Parameter_Specification (Loc,
596 Defining_Identifier => X,
597 Parameter_Type => New_Occurrence_Of (R_Type, Loc)));
600 Make_VS_If (R_Type, Discriminant_Specifications (Def)));
601 Append_List_To (Stmts, Make_VS_Case (R_Type, Comps));
604 Make_Simple_Return_Statement (Loc,
605 Expression => New_Occurrence_Of (Standard_True, Loc)));
608 Make_Subprogram_Body (Loc,
610 Make_Function_Specification (Loc,
611 Defining_Unit_Name => Func_Id,
612 Parameter_Specifications => Pspecs,
613 Result_Definition => New_Occurrence_Of (Standard_Boolean, Loc)),
614 Declarations => New_List,
615 Handled_Statement_Sequence =>
616 Make_Handled_Sequence_Of_Statements (Loc, Statements => Stmts)),
617 Suppress => Discriminant_Check);
619 if not Debug_Generated_Code then
620 Set_Debug_Info_Off (Func_Id);
623 Set_Is_Pure (Func_Id);
625 end Build_Record_VS_Func;
627 ----------------------------------
628 -- Compile_Stream_Body_In_Scope --
629 ----------------------------------
631 procedure Compile_Stream_Body_In_Scope
637 C_Type : constant Entity_Id := Base_Type (Component_Type (Arr));
638 Curr : constant Entity_Id := Current_Scope;
639 Install : Boolean := False;
640 Scop : Entity_Id := Scope (Arr);
644 and then not In_Open_Scopes (Scop)
645 and then Ekind (Scop) = E_Package
650 -- The component type may be private, in which case we install its
651 -- full view to compile the subprogram.
653 -- The component type may be private, in which case we install its
654 -- full view to compile the subprogram. We do not do this if the
655 -- type has a Stream_Convert pragma, which indicates that there are
656 -- special stream-processing operations for that type (for example
657 -- Unbounded_String and its wide varieties).
659 Scop := Scope (C_Type);
661 if Is_Private_Type (C_Type)
662 and then Present (Full_View (C_Type))
663 and then not In_Open_Scopes (Scop)
664 and then Ekind (Scop) = E_Package
665 and then No (Get_Stream_Convert_Pragma (C_Type))
671 -- If we are within an instance body, then all visibility has been
672 -- established already and there is no need to install the package.
674 if Install and then not In_Instance_Body then
676 Install_Visible_Declarations (Scop);
677 Install_Private_Declarations (Scop);
679 -- The entities in the package are now visible, but the generated
680 -- stream entity must appear in the current scope (usually an
681 -- enclosing stream function) so that itypes all have their proper
690 Insert_Action (N, Decl);
692 Insert_Action (N, Decl, Suppress => All_Checks);
697 -- Remove extra copy of current scope, and package itself
700 End_Package_Scope (Scop);
702 end Compile_Stream_Body_In_Scope;
704 -----------------------------------
705 -- Expand_Access_To_Protected_Op --
706 -----------------------------------
708 procedure Expand_Access_To_Protected_Op
713 -- The value of the attribute_reference is a record containing two
714 -- fields: an access to the protected object, and an access to the
715 -- subprogram itself. The prefix is a selected component.
717 Loc : constant Source_Ptr := Sloc (N);
719 Btyp : constant Entity_Id := Base_Type (Typ);
722 E_T : constant Entity_Id := Equivalent_Type (Btyp);
723 Acc : constant Entity_Id :=
724 Etype (Next_Component (First_Component (E_T)));
728 -- Start of processing for Expand_Access_To_Protected_Op
731 -- Within the body of the protected type, the prefix designates a local
732 -- operation, and the object is the first parameter of the corresponding
733 -- protected body of the current enclosing operation.
735 if Is_Entity_Name (Pref) then
736 -- All indirect calls are external calls, so must do locking and
737 -- barrier reevaluation, even if the 'Access occurs within the
738 -- protected body. Hence the call to External_Subprogram, as opposed
739 -- to Protected_Body_Subprogram, below. See RM-9.5(5). This means
740 -- that indirect calls from within the same protected body will
741 -- deadlock, as allowed by RM-9.5.1(8,15,17).
743 Sub := New_Occurrence_Of (External_Subprogram (Entity (Pref)), Loc);
745 -- Don't traverse the scopes when the attribute occurs within an init
746 -- proc, because we directly use the _init formal of the init proc in
749 Curr := Current_Scope;
750 if not Is_Init_Proc (Curr) then
751 pragma Assert (In_Open_Scopes (Scope (Entity (Pref))));
753 while Scope (Curr) /= Scope (Entity (Pref)) loop
754 Curr := Scope (Curr);
758 -- In case of protected entries the first formal of its Protected_
759 -- Body_Subprogram is the address of the object.
761 if Ekind (Curr) = E_Entry then
765 (Protected_Body_Subprogram (Curr)), Loc);
767 -- If the current scope is an init proc, then use the address of the
768 -- _init formal as the object reference.
770 elsif Is_Init_Proc (Curr) then
772 Make_Attribute_Reference (Loc,
773 Prefix => New_Occurrence_Of (First_Formal (Curr), Loc),
774 Attribute_Name => Name_Address);
776 -- In case of protected subprograms the first formal of its
777 -- Protected_Body_Subprogram is the object and we get its address.
781 Make_Attribute_Reference (Loc,
785 (Protected_Body_Subprogram (Curr)), Loc),
786 Attribute_Name => Name_Address);
789 -- Case where the prefix is not an entity name. Find the
790 -- version of the protected operation to be called from
791 -- outside the protected object.
797 (Entity (Selector_Name (Pref))), Loc);
800 Make_Attribute_Reference (Loc,
801 Prefix => Relocate_Node (Prefix (Pref)),
802 Attribute_Name => Name_Address);
806 Make_Attribute_Reference (Loc,
808 Attribute_Name => Name_Access);
810 -- We set the type of the access reference to the already generated
811 -- access_to_subprogram type, and declare the reference analyzed, to
812 -- prevent further expansion when the enclosing aggregate is analyzed.
814 Set_Etype (Sub_Ref, Acc);
815 Set_Analyzed (Sub_Ref);
819 Expressions => New_List (Obj_Ref, Sub_Ref));
821 -- Sub_Ref has been marked as analyzed, but we still need to make sure
822 -- Sub is correctly frozen.
824 Freeze_Before (N, Entity (Sub));
827 Analyze_And_Resolve (N, E_T);
829 -- For subsequent analysis, the node must retain its type. The backend
830 -- will replace it with the equivalent type where needed.
833 end Expand_Access_To_Protected_Op;
835 --------------------------
836 -- Expand_Fpt_Attribute --
837 --------------------------
839 procedure Expand_Fpt_Attribute
845 Loc : constant Source_Ptr := Sloc (N);
846 Typ : constant Entity_Id := Etype (N);
850 -- The function name is the selected component Attr_xxx.yyy where
851 -- Attr_xxx is the package name, and yyy is the argument Nam.
853 -- Note: it would be more usual to have separate RE entries for each
854 -- of the entities in the Fat packages, but first they have identical
855 -- names (so we would have to have lots of renaming declarations to
856 -- meet the normal RE rule of separate names for all runtime entities),
857 -- and second there would be an awful lot of them.
860 Make_Selected_Component (Loc,
861 Prefix => New_Occurrence_Of (RTE (Pkg), Loc),
862 Selector_Name => Make_Identifier (Loc, Nam));
864 -- The generated call is given the provided set of parameters, and then
865 -- wrapped in a conversion which converts the result to the target type
866 -- We use the base type as the target because a range check may be
870 Unchecked_Convert_To (Base_Type (Etype (N)),
871 Make_Function_Call (Loc,
873 Parameter_Associations => Args)));
875 Analyze_And_Resolve (N, Typ);
876 end Expand_Fpt_Attribute;
878 ----------------------------
879 -- Expand_Fpt_Attribute_R --
880 ----------------------------
882 -- The single argument is converted to its root type to call the
883 -- appropriate runtime function, with the actual call being built
884 -- by Expand_Fpt_Attribute
886 procedure Expand_Fpt_Attribute_R (N : Node_Id) is
887 E1 : constant Node_Id := First (Expressions (N));
891 Find_Fat_Info (Etype (E1), Ftp, Pkg);
893 (N, Pkg, Attribute_Name (N),
894 New_List (Unchecked_Convert_To (Ftp, Relocate_Node (E1))));
895 end Expand_Fpt_Attribute_R;
897 -----------------------------
898 -- Expand_Fpt_Attribute_RI --
899 -----------------------------
901 -- The first argument is converted to its root type and the second
902 -- argument is converted to standard long long integer to call the
903 -- appropriate runtime function, with the actual call being built
904 -- by Expand_Fpt_Attribute
906 procedure Expand_Fpt_Attribute_RI (N : Node_Id) is
907 E1 : constant Node_Id := First (Expressions (N));
910 E2 : constant Node_Id := Next (E1);
912 Find_Fat_Info (Etype (E1), Ftp, Pkg);
914 (N, Pkg, Attribute_Name (N),
916 Unchecked_Convert_To (Ftp, Relocate_Node (E1)),
917 Unchecked_Convert_To (Standard_Integer, Relocate_Node (E2))));
918 end Expand_Fpt_Attribute_RI;
920 -----------------------------
921 -- Expand_Fpt_Attribute_RR --
922 -----------------------------
924 -- The two arguments are converted to their root types to call the
925 -- appropriate runtime function, with the actual call being built
926 -- by Expand_Fpt_Attribute
928 procedure Expand_Fpt_Attribute_RR (N : Node_Id) is
929 E1 : constant Node_Id := First (Expressions (N));
930 E2 : constant Node_Id := Next (E1);
935 Find_Fat_Info (Etype (E1), Ftp, Pkg);
937 (N, Pkg, Attribute_Name (N),
939 Unchecked_Convert_To (Ftp, Relocate_Node (E1)),
940 Unchecked_Convert_To (Ftp, Relocate_Node (E2))));
941 end Expand_Fpt_Attribute_RR;
943 ---------------------------------
944 -- Expand_Loop_Entry_Attribute --
945 ---------------------------------
947 procedure Expand_Loop_Entry_Attribute (N : Node_Id) is
948 procedure Build_Conditional_Block
952 If_Stmt : out Node_Id;
953 Blk_Stmt : out Node_Id);
954 -- Create a block Blk_Stmt with an empty declarative list and a single
955 -- loop Loop_Stmt. The block is encased in an if statement If_Stmt with
956 -- condition Cond. If_Stmt is Empty when there is no condition provided.
958 function Is_Array_Iteration (N : Node_Id) return Boolean;
959 -- Determine whether loop statement N denotes an Ada 2012 iteration over
962 -----------------------------
963 -- Build_Conditional_Block --
964 -----------------------------
966 procedure Build_Conditional_Block
970 If_Stmt : out Node_Id;
971 Blk_Stmt : out Node_Id)
974 -- Do not reanalyze the original loop statement because it is simply
977 Set_Analyzed (Loop_Stmt);
980 Make_Block_Statement (Loc,
981 Declarations => New_List,
982 Handled_Statement_Sequence =>
983 Make_Handled_Sequence_Of_Statements (Loc,
984 Statements => New_List (Loop_Stmt)));
986 if Present (Cond) then
988 Make_If_Statement (Loc,
990 Then_Statements => New_List (Blk_Stmt));
994 end Build_Conditional_Block;
996 ------------------------
997 -- Is_Array_Iteration --
998 ------------------------
1000 function Is_Array_Iteration (N : Node_Id) return Boolean is
1001 Stmt : constant Node_Id := Original_Node (N);
1005 if Nkind (Stmt) = N_Loop_Statement
1006 and then Present (Iteration_Scheme (Stmt))
1007 and then Present (Iterator_Specification (Iteration_Scheme (Stmt)))
1009 Iter := Iterator_Specification (Iteration_Scheme (Stmt));
1012 Of_Present (Iter) and then Is_Array_Type (Etype (Name (Iter)));
1016 end Is_Array_Iteration;
1020 Exprs : constant List_Id := Expressions (N);
1021 Pref : constant Node_Id := Prefix (N);
1022 Typ : constant Entity_Id := Etype (Pref);
1025 CW_Temp : Entity_Id;
1028 Installed : Boolean;
1030 Loop_Id : Entity_Id;
1031 Loop_Stmt : Node_Id;
1034 Temp_Decl : Node_Id;
1035 Temp_Id : Entity_Id;
1037 -- Start of processing for Expand_Loop_Entry_Attribute
1040 -- Step 1: Find the related loop
1042 -- The loop label variant of attribute 'Loop_Entry already has all the
1043 -- information in its expression.
1045 if Present (Exprs) then
1046 Loop_Id := Entity (First (Exprs));
1047 Loop_Stmt := Label_Construct (Parent (Loop_Id));
1049 -- Climb the parent chain to find the nearest enclosing loop. Skip all
1050 -- internally generated loops for quantified expressions and for
1051 -- element iterators over multidimensional arrays: pragma applies to
1056 while Present (Loop_Stmt) loop
1057 if Nkind (Loop_Stmt) = N_Loop_Statement
1058 and then Comes_From_Source (Loop_Stmt)
1063 Loop_Stmt := Parent (Loop_Stmt);
1066 Loop_Id := Entity (Identifier (Loop_Stmt));
1069 Loc := Sloc (Loop_Stmt);
1071 -- Step 2: Transform the loop
1073 -- The loop has already been transformed during the expansion of a prior
1074 -- 'Loop_Entry attribute. Retrieve the declarative list of the block.
1076 if Has_Loop_Entry_Attributes (Loop_Id) then
1078 -- When the related loop name appears as the argument of attribute
1079 -- Loop_Entry, the corresponding label construct is the generated
1080 -- block statement. This is because the expander reuses the label.
1082 if Nkind (Loop_Stmt) = N_Block_Statement then
1083 Decls := Declarations (Loop_Stmt);
1085 -- In all other cases, the loop must appear in the handled sequence
1086 -- of statements of the generated block.
1090 (Nkind (Parent (Loop_Stmt)) = N_Handled_Sequence_Of_Statements
1092 Nkind (Parent (Parent (Loop_Stmt))) = N_Block_Statement);
1094 Decls := Declarations (Parent (Parent (Loop_Stmt)));
1099 -- Transform the loop into a conditional block
1102 Set_Has_Loop_Entry_Attributes (Loop_Id);
1103 Scheme := Iteration_Scheme (Loop_Stmt);
1105 -- Infinite loops are transformed into:
1108 -- Temp1 : constant <type of Pref1> := <Pref1>;
1110 -- TempN : constant <type of PrefN> := <PrefN>;
1113 -- <original source statements with attribute rewrites>
1118 Build_Conditional_Block (Loc,
1120 Loop_Stmt => Relocate_Node (Loop_Stmt),
1126 -- While loops are transformed into:
1128 -- function Fnn return Boolean is
1130 -- <condition actions>
1131 -- return <condition>;
1136 -- Temp1 : constant <type of Pref1> := <Pref1>;
1138 -- TempN : constant <type of PrefN> := <PrefN>;
1141 -- <original source statements with attribute rewrites>
1142 -- exit when not Fnn;
1147 -- Note that loops over iterators and containers are already
1148 -- converted into while loops.
1150 elsif Present (Condition (Scheme)) then
1152 Func_Decl : Node_Id;
1153 Func_Id : Entity_Id;
1157 -- Wrap the condition of the while loop in a Boolean function.
1158 -- This avoids the duplication of the same code which may lead
1159 -- to gigi issues with respect to multiple declaration of the
1160 -- same entity in the presence of side effects or checks. Note
1161 -- that the condition actions must also be relocated to the
1162 -- wrapping function.
1165 -- <condition actions>
1166 -- return <condition>;
1168 if Present (Condition_Actions (Scheme)) then
1169 Stmts := Condition_Actions (Scheme);
1175 Make_Simple_Return_Statement (Loc,
1176 Expression => Relocate_Node (Condition (Scheme))));
1179 -- function Fnn return Boolean is
1184 Func_Id := Make_Temporary (Loc, 'F');
1186 Make_Subprogram_Body (Loc,
1188 Make_Function_Specification (Loc,
1189 Defining_Unit_Name => Func_Id,
1190 Result_Definition =>
1191 New_Occurrence_Of (Standard_Boolean, Loc)),
1192 Declarations => Empty_List,
1193 Handled_Statement_Sequence =>
1194 Make_Handled_Sequence_Of_Statements (Loc,
1195 Statements => Stmts));
1197 -- The function is inserted before the related loop. Make sure
1198 -- to analyze it in the context of the loop's enclosing scope.
1200 Push_Scope (Scope (Loop_Id));
1201 Insert_Action (Loop_Stmt, Func_Decl);
1204 -- Transform the original while loop into an infinite loop
1205 -- where the last statement checks the negated condition. This
1206 -- placement ensures that the condition will not be evaluated
1207 -- twice on the first iteration.
1209 Set_Iteration_Scheme (Loop_Stmt, Empty);
1213 -- exit when not Fnn;
1215 Append_To (Statements (Loop_Stmt),
1216 Make_Exit_Statement (Loc,
1220 Make_Function_Call (Loc,
1221 Name => New_Occurrence_Of (Func_Id, Loc)))));
1223 Build_Conditional_Block (Loc,
1225 Make_Function_Call (Loc,
1226 Name => New_Occurrence_Of (Func_Id, Loc)),
1227 Loop_Stmt => Relocate_Node (Loop_Stmt),
1232 -- Ada 2012 iteration over an array is transformed into:
1234 -- if <Array_Nam>'Length (1) > 0
1235 -- and then <Array_Nam>'Length (N) > 0
1238 -- Temp1 : constant <type of Pref1> := <Pref1>;
1240 -- TempN : constant <type of PrefN> := <PrefN>;
1242 -- for X in ... loop -- multiple loops depending on dims
1243 -- <original source statements with attribute rewrites>
1248 elsif Is_Array_Iteration (Loop_Stmt) then
1250 Array_Nam : constant Entity_Id :=
1251 Entity (Name (Iterator_Specification
1252 (Iteration_Scheme (Original_Node (Loop_Stmt)))));
1253 Num_Dims : constant Pos :=
1254 Number_Dimensions (Etype (Array_Nam));
1255 Cond : Node_Id := Empty;
1259 -- Generate a check which determines whether all dimensions of
1260 -- the array are non-null.
1262 for Dim in 1 .. Num_Dims loop
1266 Make_Attribute_Reference (Loc,
1267 Prefix => New_Occurrence_Of (Array_Nam, Loc),
1268 Attribute_Name => Name_Length,
1269 Expressions => New_List (
1270 Make_Integer_Literal (Loc, Dim))),
1272 Make_Integer_Literal (Loc, 0));
1280 Right_Opnd => Check);
1284 Build_Conditional_Block (Loc,
1286 Loop_Stmt => Relocate_Node (Loop_Stmt),
1291 -- For loops are transformed into:
1293 -- if <Low> <= <High> then
1295 -- Temp1 : constant <type of Pref1> := <Pref1>;
1297 -- TempN : constant <type of PrefN> := <PrefN>;
1299 -- for <Def_Id> in <Low> .. <High> loop
1300 -- <original source statements with attribute rewrites>
1305 elsif Present (Loop_Parameter_Specification (Scheme)) then
1307 Loop_Spec : constant Node_Id :=
1308 Loop_Parameter_Specification (Scheme);
1313 Subt_Def := Discrete_Subtype_Definition (Loop_Spec);
1315 -- When the loop iterates over a subtype indication with a
1316 -- range, use the low and high bounds of the subtype itself.
1318 if Nkind (Subt_Def) = N_Subtype_Indication then
1319 Subt_Def := Scalar_Range (Etype (Subt_Def));
1322 pragma Assert (Nkind (Subt_Def) = N_Range);
1329 Left_Opnd => New_Copy_Tree (Low_Bound (Subt_Def)),
1330 Right_Opnd => New_Copy_Tree (High_Bound (Subt_Def)));
1332 Build_Conditional_Block (Loc,
1334 Loop_Stmt => Relocate_Node (Loop_Stmt),
1340 Decls := Declarations (Blk);
1343 -- Step 3: Create a constant to capture the value of the prefix at the
1344 -- entry point into the loop.
1346 Temp_Id := Make_Temporary (Loc, 'P');
1348 -- Preserve the tag of the prefix by offering a specific view of the
1349 -- class-wide version of the prefix.
1351 if Is_Tagged_Type (Typ) then
1354 -- CW_Temp : constant Typ'Class := Typ'Class (Pref);
1356 CW_Temp := Make_Temporary (Loc, 'T');
1357 CW_Typ := Class_Wide_Type (Typ);
1360 Make_Object_Declaration (Loc,
1361 Defining_Identifier => CW_Temp,
1362 Constant_Present => True,
1363 Object_Definition => New_Occurrence_Of (CW_Typ, Loc),
1365 Convert_To (CW_Typ, Relocate_Node (Pref)));
1366 Append_To (Decls, CW_Decl);
1369 -- Temp : Typ renames Typ (CW_Temp);
1372 Make_Object_Renaming_Declaration (Loc,
1373 Defining_Identifier => Temp_Id,
1374 Subtype_Mark => New_Occurrence_Of (Typ, Loc),
1376 Convert_To (Typ, New_Occurrence_Of (CW_Temp, Loc)));
1377 Append_To (Decls, Temp_Decl);
1385 -- Temp : constant Typ := Pref;
1388 Make_Object_Declaration (Loc,
1389 Defining_Identifier => Temp_Id,
1390 Constant_Present => True,
1391 Object_Definition => New_Occurrence_Of (Typ, Loc),
1392 Expression => Relocate_Node (Pref));
1393 Append_To (Decls, Temp_Decl);
1396 -- Step 4: Analyze all bits
1398 Installed := Current_Scope = Scope (Loop_Id);
1400 -- Depending on the pracement of attribute 'Loop_Entry relative to the
1401 -- associated loop, ensure the proper visibility for analysis.
1403 if not Installed then
1404 Push_Scope (Scope (Loop_Id));
1407 -- The analysis of the conditional block takes care of the constant
1410 if Present (Result) then
1411 Rewrite (Loop_Stmt, Result);
1412 Analyze (Loop_Stmt);
1414 -- The conditional block was analyzed when a previous 'Loop_Entry was
1415 -- expanded. There is no point in reanalyzing the block, simply analyze
1416 -- the declaration of the constant.
1419 if Present (CW_Decl) then
1423 Analyze (Temp_Decl);
1426 Rewrite (N, New_Occurrence_Of (Temp_Id, Loc));
1429 if not Installed then
1432 end Expand_Loop_Entry_Attribute;
1434 ------------------------------
1435 -- Expand_Min_Max_Attribute --
1436 ------------------------------
1438 procedure Expand_Min_Max_Attribute (N : Node_Id) is
1440 -- Min and Max are handled by the back end (except that static cases
1441 -- have already been evaluated during semantic processing, although the
1442 -- back end should not count on this). The one bit of special processing
1443 -- required in the normal case is that these two attributes typically
1444 -- generate conditionals in the code, so check the relevant restriction.
1446 Check_Restriction (No_Implicit_Conditionals, N);
1448 -- In Modify_Tree_For_C mode, we rewrite as an if expression
1450 if Modify_Tree_For_C then
1452 Loc : constant Source_Ptr := Sloc (N);
1453 Typ : constant Entity_Id := Etype (N);
1454 Expr : constant Node_Id := First (Expressions (N));
1455 Left : constant Node_Id := Relocate_Node (Expr);
1456 Right : constant Node_Id := Relocate_Node (Next (Expr));
1458 function Make_Compare (Left, Right : Node_Id) return Node_Id;
1459 -- Returns Left >= Right for Max, Left <= Right for Min
1465 function Make_Compare (Left, Right : Node_Id) return Node_Id is
1467 if Attribute_Name (N) = Name_Max then
1471 Right_Opnd => Right);
1476 Right_Opnd => Right);
1480 -- Start of processing for Min_Max
1483 -- If both Left and Right are side effect free, then we can just
1484 -- use Duplicate_Expr to duplicate the references and return
1486 -- (if Left >=|<= Right then Left else Right)
1488 if Side_Effect_Free (Left) and then Side_Effect_Free (Right) then
1490 Make_If_Expression (Loc,
1491 Expressions => New_List (
1492 Make_Compare (Left, Right),
1493 Duplicate_Subexpr_No_Checks (Left),
1494 Duplicate_Subexpr_No_Checks (Right))));
1496 -- Otherwise we generate declarations to capture the values.
1498 -- The translation is
1501 -- T1 : constant typ := Left;
1502 -- T2 : constant typ := Right;
1504 -- (if T1 >=|<= T2 then T1 else T2)
1509 T1 : constant Entity_Id := Make_Temporary (Loc, 'T', Left);
1510 T2 : constant Entity_Id := Make_Temporary (Loc, 'T', Right);
1514 Make_Expression_With_Actions (Loc,
1515 Actions => New_List (
1516 Make_Object_Declaration (Loc,
1517 Defining_Identifier => T1,
1518 Constant_Present => True,
1519 Object_Definition =>
1520 New_Occurrence_Of (Etype (Left), Loc),
1521 Expression => Relocate_Node (Left)),
1523 Make_Object_Declaration (Loc,
1524 Defining_Identifier => T2,
1525 Constant_Present => True,
1526 Object_Definition =>
1527 New_Occurrence_Of (Etype (Right), Loc),
1528 Expression => Relocate_Node (Right))),
1531 Make_If_Expression (Loc,
1532 Expressions => New_List (
1534 (New_Occurrence_Of (T1, Loc),
1535 New_Occurrence_Of (T2, Loc)),
1536 New_Occurrence_Of (T1, Loc),
1537 New_Occurrence_Of (T2, Loc)))));
1541 Analyze_And_Resolve (N, Typ);
1544 end Expand_Min_Max_Attribute;
1546 ----------------------------------
1547 -- Expand_N_Attribute_Reference --
1548 ----------------------------------
1550 procedure Expand_N_Attribute_Reference (N : Node_Id) is
1551 Loc : constant Source_Ptr := Sloc (N);
1552 Typ : constant Entity_Id := Etype (N);
1553 Btyp : constant Entity_Id := Base_Type (Typ);
1554 Pref : constant Node_Id := Prefix (N);
1555 Ptyp : constant Entity_Id := Etype (Pref);
1556 Exprs : constant List_Id := Expressions (N);
1557 Id : constant Attribute_Id := Get_Attribute_Id (Attribute_Name (N));
1559 procedure Rewrite_Stream_Proc_Call (Pname : Entity_Id);
1560 -- Rewrites a stream attribute for Read, Write or Output with the
1561 -- procedure call. Pname is the entity for the procedure to call.
1563 ------------------------------
1564 -- Rewrite_Stream_Proc_Call --
1565 ------------------------------
1567 procedure Rewrite_Stream_Proc_Call (Pname : Entity_Id) is
1568 Item : constant Node_Id := Next (First (Exprs));
1569 Formal : constant Entity_Id := Next_Formal (First_Formal (Pname));
1570 Formal_Typ : constant Entity_Id := Etype (Formal);
1571 Is_Written : constant Boolean := (Ekind (Formal) /= E_In_Parameter);
1574 -- The expansion depends on Item, the second actual, which is
1575 -- the object being streamed in or out.
1577 -- If the item is a component of a packed array type, and
1578 -- a conversion is needed on exit, we introduce a temporary to
1579 -- hold the value, because otherwise the packed reference will
1580 -- not be properly expanded.
1582 if Nkind (Item) = N_Indexed_Component
1583 and then Is_Packed (Base_Type (Etype (Prefix (Item))))
1584 and then Base_Type (Etype (Item)) /= Base_Type (Formal_Typ)
1588 Temp : constant Entity_Id := Make_Temporary (Loc, 'V');
1594 Make_Object_Declaration (Loc,
1595 Defining_Identifier => Temp,
1596 Object_Definition =>
1597 New_Occurrence_Of (Formal_Typ, Loc));
1598 Set_Etype (Temp, Formal_Typ);
1601 Make_Assignment_Statement (Loc,
1602 Name => New_Copy_Tree (Item),
1604 Unchecked_Convert_To
1605 (Etype (Item), New_Occurrence_Of (Temp, Loc)));
1607 Rewrite (Item, New_Occurrence_Of (Temp, Loc));
1611 Make_Procedure_Call_Statement (Loc,
1612 Name => New_Occurrence_Of (Pname, Loc),
1613 Parameter_Associations => Exprs),
1616 Rewrite (N, Make_Null_Statement (Loc));
1621 -- For the class-wide dispatching cases, and for cases in which
1622 -- the base type of the second argument matches the base type of
1623 -- the corresponding formal parameter (that is to say the stream
1624 -- operation is not inherited), we are all set, and can use the
1625 -- argument unchanged.
1627 -- For all other cases we do an unchecked conversion of the second
1628 -- parameter to the type of the formal of the procedure we are
1629 -- calling. This deals with the private type cases, and with going
1630 -- to the root type as required in elementary type case.
1632 if not Is_Class_Wide_Type (Entity (Pref))
1633 and then not Is_Class_Wide_Type (Etype (Item))
1634 and then Base_Type (Etype (Item)) /= Base_Type (Formal_Typ)
1637 Unchecked_Convert_To (Formal_Typ, Relocate_Node (Item)));
1639 -- For untagged derived types set Assignment_OK, to prevent
1640 -- copies from being created when the unchecked conversion
1641 -- is expanded (which would happen in Remove_Side_Effects
1642 -- if Expand_N_Unchecked_Conversion were allowed to call
1643 -- Force_Evaluation). The copy could violate Ada semantics in
1644 -- cases such as an actual that is an out parameter. Note that
1645 -- this approach is also used in exp_ch7 for calls to controlled
1646 -- type operations to prevent problems with actuals wrapped in
1647 -- unchecked conversions.
1649 if Is_Untagged_Derivation (Etype (Expression (Item))) then
1650 Set_Assignment_OK (Item);
1654 -- The stream operation to call may be a renaming created by an
1655 -- attribute definition clause, and may not be frozen yet. Ensure
1656 -- that it has the necessary extra formals.
1658 if not Is_Frozen (Pname) then
1659 Create_Extra_Formals (Pname);
1662 -- And now rewrite the call
1665 Make_Procedure_Call_Statement (Loc,
1666 Name => New_Occurrence_Of (Pname, Loc),
1667 Parameter_Associations => Exprs));
1670 end Rewrite_Stream_Proc_Call;
1672 -- Start of processing for Expand_N_Attribute_Reference
1675 -- Do required validity checking, if enabled. Do not apply check to
1676 -- output parameters of an Asm instruction, since the value of this
1677 -- is not set till after the attribute has been elaborated, and do
1678 -- not apply the check to the arguments of a 'Read or 'Input attribute
1679 -- reference since the scalar argument is an OUT scalar.
1681 if Validity_Checks_On and then Validity_Check_Operands
1682 and then Id /= Attribute_Asm_Output
1683 and then Id /= Attribute_Read
1684 and then Id /= Attribute_Input
1689 Expr := First (Expressions (N));
1690 while Present (Expr) loop
1691 Ensure_Valid (Expr);
1697 -- Ada 2005 (AI-318-02): If attribute prefix is a call to a build-in-
1698 -- place function, then a temporary return object needs to be created
1699 -- and access to it must be passed to the function. Currently we limit
1700 -- such functions to those with inherently limited result subtypes, but
1701 -- eventually we plan to expand the functions that are treated as
1702 -- build-in-place to include other composite result types.
1704 if Ada_Version >= Ada_2005
1705 and then Is_Build_In_Place_Function_Call (Pref)
1707 Make_Build_In_Place_Call_In_Anonymous_Context (Pref);
1710 -- If prefix is a protected type name, this is a reference to the
1711 -- current instance of the type. For a component definition, nothing
1712 -- to do (expansion will occur in the init proc). In other contexts,
1713 -- rewrite into reference to current instance.
1715 if Is_Protected_Self_Reference (Pref)
1717 (Nkind_In (Parent (N), N_Index_Or_Discriminant_Constraint,
1718 N_Discriminant_Association)
1719 and then Nkind (Parent (Parent (Parent (Parent (N))))) =
1720 N_Component_Definition)
1722 -- No action needed for these attributes since the current instance
1723 -- will be rewritten to be the name of the _object parameter
1724 -- associated with the enclosing protected subprogram (see below).
1726 and then Id /= Attribute_Access
1727 and then Id /= Attribute_Unchecked_Access
1728 and then Id /= Attribute_Unrestricted_Access
1730 Rewrite (Pref, Concurrent_Ref (Pref));
1734 -- Remaining processing depends on specific attribute
1736 -- Note: individual sections of the following case statement are
1737 -- allowed to assume there is no code after the case statement, and
1738 -- are legitimately allowed to execute return statements if they have
1739 -- nothing more to do.
1743 -- Attributes related to Ada 2012 iterators
1745 when Attribute_Constant_Indexing |
1746 Attribute_Default_Iterator |
1747 Attribute_Implicit_Dereference |
1748 Attribute_Iterable |
1749 Attribute_Iterator_Element |
1750 Attribute_Variable_Indexing =>
1753 -- Internal attributes used to deal with Ada 2012 delayed aspects. These
1754 -- were already rejected by the parser. Thus they shouldn't appear here.
1756 when Internal_Attribute_Id =>
1757 raise Program_Error;
1763 when Attribute_Access |
1764 Attribute_Unchecked_Access |
1765 Attribute_Unrestricted_Access =>
1767 Access_Cases : declare
1768 Ref_Object : constant Node_Id := Get_Referenced_Object (Pref);
1769 Btyp_DDT : Entity_Id;
1771 function Enclosing_Object (N : Node_Id) return Node_Id;
1772 -- If N denotes a compound name (selected component, indexed
1773 -- component, or slice), returns the name of the outermost such
1774 -- enclosing object. Otherwise returns N. If the object is a
1775 -- renaming, then the renamed object is returned.
1777 ----------------------
1778 -- Enclosing_Object --
1779 ----------------------
1781 function Enclosing_Object (N : Node_Id) return Node_Id is
1786 while Nkind_In (Obj_Name, N_Selected_Component,
1787 N_Indexed_Component,
1790 Obj_Name := Prefix (Obj_Name);
1793 return Get_Referenced_Object (Obj_Name);
1794 end Enclosing_Object;
1796 -- Local declarations
1798 Enc_Object : constant Node_Id := Enclosing_Object (Ref_Object);
1800 -- Start of processing for Access_Cases
1803 Btyp_DDT := Designated_Type (Btyp);
1805 -- Handle designated types that come from the limited view
1807 if From_Limited_With (Btyp_DDT)
1808 and then Has_Non_Limited_View (Btyp_DDT)
1810 Btyp_DDT := Non_Limited_View (Btyp_DDT);
1813 -- In order to improve the text of error messages, the designated
1814 -- type of access-to-subprogram itypes is set by the semantics as
1815 -- the associated subprogram entity (see sem_attr). Now we replace
1816 -- such node with the proper E_Subprogram_Type itype.
1818 if Id = Attribute_Unrestricted_Access
1819 and then Is_Subprogram (Directly_Designated_Type (Typ))
1821 -- The following conditions ensure that this special management
1822 -- is done only for "Address!(Prim'Unrestricted_Access)" nodes.
1823 -- At this stage other cases in which the designated type is
1824 -- still a subprogram (instead of an E_Subprogram_Type) are
1825 -- wrong because the semantics must have overridden the type of
1826 -- the node with the type imposed by the context.
1828 if Nkind (Parent (N)) = N_Unchecked_Type_Conversion
1829 and then Etype (Parent (N)) = RTE (RE_Prim_Ptr)
1831 Set_Etype (N, RTE (RE_Prim_Ptr));
1835 Subp : constant Entity_Id :=
1836 Directly_Designated_Type (Typ);
1838 Extra : Entity_Id := Empty;
1839 New_Formal : Entity_Id;
1840 Old_Formal : Entity_Id := First_Formal (Subp);
1841 Subp_Typ : Entity_Id;
1844 Subp_Typ := Create_Itype (E_Subprogram_Type, N);
1845 Set_Etype (Subp_Typ, Etype (Subp));
1846 Set_Returns_By_Ref (Subp_Typ, Returns_By_Ref (Subp));
1848 if Present (Old_Formal) then
1849 New_Formal := New_Copy (Old_Formal);
1850 Set_First_Entity (Subp_Typ, New_Formal);
1853 Set_Scope (New_Formal, Subp_Typ);
1854 Etyp := Etype (New_Formal);
1856 -- Handle itypes. There is no need to duplicate
1857 -- here the itypes associated with record types
1858 -- (i.e the implicit full view of private types).
1861 and then Ekind (Base_Type (Etyp)) /= E_Record_Type
1863 Extra := New_Copy (Etyp);
1864 Set_Parent (Extra, New_Formal);
1865 Set_Etype (New_Formal, Extra);
1866 Set_Scope (Extra, Subp_Typ);
1869 Extra := New_Formal;
1870 Next_Formal (Old_Formal);
1871 exit when No (Old_Formal);
1873 Set_Next_Entity (New_Formal,
1874 New_Copy (Old_Formal));
1875 Next_Entity (New_Formal);
1878 Set_Next_Entity (New_Formal, Empty);
1879 Set_Last_Entity (Subp_Typ, Extra);
1882 -- Now that the explicit formals have been duplicated,
1883 -- any extra formals needed by the subprogram must be
1886 if Present (Extra) then
1887 Set_Extra_Formal (Extra, Empty);
1890 Create_Extra_Formals (Subp_Typ);
1891 Set_Directly_Designated_Type (Typ, Subp_Typ);
1896 if Is_Access_Protected_Subprogram_Type (Btyp) then
1897 Expand_Access_To_Protected_Op (N, Pref, Typ);
1899 -- If prefix is a type name, this is a reference to the current
1900 -- instance of the type, within its initialization procedure.
1902 elsif Is_Entity_Name (Pref)
1903 and then Is_Type (Entity (Pref))
1910 -- If the current instance name denotes a task type, then
1911 -- the access attribute is rewritten to be the name of the
1912 -- "_task" parameter associated with the task type's task
1913 -- procedure. An unchecked conversion is applied to ensure
1914 -- a type match in cases of expander-generated calls (e.g.
1917 if Is_Task_Type (Entity (Pref)) then
1919 First_Entity (Get_Task_Body_Procedure (Entity (Pref)));
1920 while Present (Formal) loop
1921 exit when Chars (Formal) = Name_uTask;
1922 Next_Entity (Formal);
1925 pragma Assert (Present (Formal));
1928 Unchecked_Convert_To (Typ,
1929 New_Occurrence_Of (Formal, Loc)));
1932 elsif Is_Protected_Type (Entity (Pref)) then
1934 -- No action needed for current instance located in a
1935 -- component definition (expansion will occur in the
1938 if Is_Protected_Type (Current_Scope) then
1941 -- If the current instance reference is located in a
1942 -- protected subprogram or entry then rewrite the access
1943 -- attribute to be the name of the "_object" parameter.
1944 -- An unchecked conversion is applied to ensure a type
1945 -- match in cases of expander-generated calls (e.g. init
1948 -- The code may be nested in a block, so find enclosing
1949 -- scope that is a protected operation.
1956 Subp := Current_Scope;
1957 while Ekind_In (Subp, E_Loop, E_Block) loop
1958 Subp := Scope (Subp);
1963 (Protected_Body_Subprogram (Subp));
1965 -- For a protected subprogram the _Object parameter
1966 -- is the protected record, so we create an access
1967 -- to it. The _Object parameter of an entry is an
1970 if Ekind (Subp) = E_Entry then
1972 Unchecked_Convert_To (Typ,
1973 New_Occurrence_Of (Formal, Loc)));
1978 Unchecked_Convert_To (Typ,
1979 Make_Attribute_Reference (Loc,
1980 Attribute_Name => Name_Unrestricted_Access,
1982 New_Occurrence_Of (Formal, Loc))));
1983 Analyze_And_Resolve (N);
1988 -- The expression must appear in a default expression,
1989 -- (which in the initialization procedure is the right-hand
1990 -- side of an assignment), and not in a discriminant
1995 while Present (Par) loop
1996 exit when Nkind (Par) = N_Assignment_Statement;
1998 if Nkind (Par) = N_Component_Declaration then
2002 Par := Parent (Par);
2005 if Present (Par) then
2007 Make_Attribute_Reference (Loc,
2008 Prefix => Make_Identifier (Loc, Name_uInit),
2009 Attribute_Name => Attribute_Name (N)));
2011 Analyze_And_Resolve (N, Typ);
2016 -- If the prefix of an Access attribute is a dereference of an
2017 -- access parameter (or a renaming of such a dereference, or a
2018 -- subcomponent of such a dereference) and the context is a
2019 -- general access type (including the type of an object or
2020 -- component with an access_definition, but not the anonymous
2021 -- type of an access parameter or access discriminant), then
2022 -- apply an accessibility check to the access parameter. We used
2023 -- to rewrite the access parameter as a type conversion, but that
2024 -- could only be done if the immediate prefix of the Access
2025 -- attribute was the dereference, and didn't handle cases where
2026 -- the attribute is applied to a subcomponent of the dereference,
2027 -- since there's generally no available, appropriate access type
2028 -- to convert to in that case. The attribute is passed as the
2029 -- point to insert the check, because the access parameter may
2030 -- come from a renaming, possibly in a different scope, and the
2031 -- check must be associated with the attribute itself.
2033 elsif Id = Attribute_Access
2034 and then Nkind (Enc_Object) = N_Explicit_Dereference
2035 and then Is_Entity_Name (Prefix (Enc_Object))
2036 and then (Ekind (Btyp) = E_General_Access_Type
2037 or else Is_Local_Anonymous_Access (Btyp))
2038 and then Ekind (Entity (Prefix (Enc_Object))) in Formal_Kind
2039 and then Ekind (Etype (Entity (Prefix (Enc_Object))))
2040 = E_Anonymous_Access_Type
2041 and then Present (Extra_Accessibility
2042 (Entity (Prefix (Enc_Object))))
2044 Apply_Accessibility_Check (Prefix (Enc_Object), Typ, N);
2046 -- Ada 2005 (AI-251): If the designated type is an interface we
2047 -- add an implicit conversion to force the displacement of the
2048 -- pointer to reference the secondary dispatch table.
2050 elsif Is_Interface (Btyp_DDT)
2051 and then (Comes_From_Source (N)
2052 or else Comes_From_Source (Ref_Object)
2053 or else (Nkind (Ref_Object) in N_Has_Chars
2054 and then Chars (Ref_Object) = Name_uInit))
2056 if Nkind (Ref_Object) /= N_Explicit_Dereference then
2058 -- No implicit conversion required if types match, or if
2059 -- the prefix is the class_wide_type of the interface. In
2060 -- either case passing an object of the interface type has
2061 -- already set the pointer correctly.
2063 if Btyp_DDT = Etype (Ref_Object)
2064 or else (Is_Class_Wide_Type (Etype (Ref_Object))
2066 Class_Wide_Type (Btyp_DDT) = Etype (Ref_Object))
2071 Rewrite (Prefix (N),
2072 Convert_To (Btyp_DDT,
2073 New_Copy_Tree (Prefix (N))));
2075 Analyze_And_Resolve (Prefix (N), Btyp_DDT);
2078 -- When the object is an explicit dereference, convert the
2079 -- dereference's prefix.
2083 Obj_DDT : constant Entity_Id :=
2085 (Directly_Designated_Type
2086 (Etype (Prefix (Ref_Object))));
2088 -- No implicit conversion required if designated types
2089 -- match, or if we have an unrestricted access.
2091 if Obj_DDT /= Btyp_DDT
2092 and then Id /= Attribute_Unrestricted_Access
2093 and then not (Is_Class_Wide_Type (Obj_DDT)
2094 and then Etype (Obj_DDT) = Btyp_DDT)
2098 New_Copy_Tree (Prefix (Ref_Object))));
2099 Analyze_And_Resolve (N, Typ);
2110 -- Transforms 'Adjacent into a call to the floating-point attribute
2111 -- function Adjacent in Fat_xxx (where xxx is the root type)
2113 when Attribute_Adjacent =>
2114 Expand_Fpt_Attribute_RR (N);
2120 when Attribute_Address => Address : declare
2121 Task_Proc : Entity_Id;
2124 -- If the prefix is a task or a task type, the useful address is that
2125 -- of the procedure for the task body, i.e. the actual program unit.
2126 -- We replace the original entity with that of the procedure.
2128 if Is_Entity_Name (Pref)
2129 and then Is_Task_Type (Entity (Pref))
2131 Task_Proc := Next_Entity (Root_Type (Ptyp));
2133 while Present (Task_Proc) loop
2134 exit when Ekind (Task_Proc) = E_Procedure
2135 and then Etype (First_Formal (Task_Proc)) =
2136 Corresponding_Record_Type (Ptyp);
2137 Next_Entity (Task_Proc);
2140 if Present (Task_Proc) then
2141 Set_Entity (Pref, Task_Proc);
2142 Set_Etype (Pref, Etype (Task_Proc));
2145 -- Similarly, the address of a protected operation is the address
2146 -- of the corresponding protected body, regardless of the protected
2147 -- object from which it is selected.
2149 elsif Nkind (Pref) = N_Selected_Component
2150 and then Is_Subprogram (Entity (Selector_Name (Pref)))
2151 and then Is_Protected_Type (Scope (Entity (Selector_Name (Pref))))
2155 External_Subprogram (Entity (Selector_Name (Pref))), Loc));
2157 elsif Nkind (Pref) = N_Explicit_Dereference
2158 and then Ekind (Ptyp) = E_Subprogram_Type
2159 and then Convention (Ptyp) = Convention_Protected
2161 -- The prefix is be a dereference of an access_to_protected_
2162 -- subprogram. The desired address is the second component of
2163 -- the record that represents the access.
2166 Addr : constant Entity_Id := Etype (N);
2167 Ptr : constant Node_Id := Prefix (Pref);
2168 T : constant Entity_Id :=
2169 Equivalent_Type (Base_Type (Etype (Ptr)));
2173 Unchecked_Convert_To (Addr,
2174 Make_Selected_Component (Loc,
2175 Prefix => Unchecked_Convert_To (T, Ptr),
2176 Selector_Name => New_Occurrence_Of (
2177 Next_Entity (First_Entity (T)), Loc))));
2179 Analyze_And_Resolve (N, Addr);
2182 -- Ada 2005 (AI-251): Class-wide interface objects are always
2183 -- "displaced" to reference the tag associated with the interface
2184 -- type. In order to obtain the real address of such objects we
2185 -- generate a call to a run-time subprogram that returns the base
2186 -- address of the object.
2188 -- This processing is not needed in the VM case, where dispatching
2189 -- issues are taken care of by the virtual machine.
2191 elsif Is_Class_Wide_Type (Ptyp)
2192 and then Is_Interface (Ptyp)
2193 and then Tagged_Type_Expansion
2194 and then not (Nkind (Pref) in N_Has_Entity
2195 and then Is_Subprogram (Entity (Pref)))
2198 Make_Function_Call (Loc,
2199 Name => New_Occurrence_Of (RTE (RE_Base_Address), Loc),
2200 Parameter_Associations => New_List (
2201 Relocate_Node (N))));
2206 -- Deal with packed array reference, other cases are handled by
2209 if Involves_Packed_Array_Reference (Pref) then
2210 Expand_Packed_Address_Reference (N);
2218 when Attribute_Alignment => Alignment : declare
2222 -- For class-wide types, X'Class'Alignment is transformed into a
2223 -- direct reference to the Alignment of the class type, so that the
2224 -- back end does not have to deal with the X'Class'Alignment
2227 if Is_Entity_Name (Pref)
2228 and then Is_Class_Wide_Type (Entity (Pref))
2230 Rewrite (Prefix (N), New_Occurrence_Of (Entity (Pref), Loc));
2233 -- For x'Alignment applied to an object of a class wide type,
2234 -- transform X'Alignment into a call to the predefined primitive
2235 -- operation _Alignment applied to X.
2237 elsif Is_Class_Wide_Type (Ptyp) then
2239 Make_Attribute_Reference (Loc,
2241 Attribute_Name => Name_Tag);
2243 New_Node := Build_Get_Alignment (Loc, New_Node);
2245 -- Case where the context is a specific integer type with which
2246 -- the original attribute was compatible. The function has a
2247 -- specific type as well, so to preserve the compatibility we
2248 -- must convert explicitly.
2250 if Typ /= Standard_Integer then
2251 New_Node := Convert_To (Typ, New_Node);
2254 Rewrite (N, New_Node);
2255 Analyze_And_Resolve (N, Typ);
2258 -- For all other cases, we just have to deal with the case of
2259 -- the fact that the result can be universal.
2262 Apply_Universal_Integer_Attribute_Checks (N);
2270 -- We compute this if a packed array reference was present, otherwise we
2271 -- leave the computation up to the back end.
2273 when Attribute_Bit =>
2274 if Involves_Packed_Array_Reference (Pref) then
2275 Expand_Packed_Bit_Reference (N);
2277 Apply_Universal_Integer_Attribute_Checks (N);
2284 -- We compute this if a component clause was present, otherwise we leave
2285 -- the computation up to the back end, since we don't know what layout
2288 -- Note that the attribute can apply to a naked record component
2289 -- in generated code (i.e. the prefix is an identifier that
2290 -- references the component or discriminant entity).
2292 when Attribute_Bit_Position => Bit_Position : declare
2296 if Nkind (Pref) = N_Identifier then
2297 CE := Entity (Pref);
2299 CE := Entity (Selector_Name (Pref));
2302 if Known_Static_Component_Bit_Offset (CE) then
2304 Make_Integer_Literal (Loc,
2305 Intval => Component_Bit_Offset (CE)));
2306 Analyze_And_Resolve (N, Typ);
2309 Apply_Universal_Integer_Attribute_Checks (N);
2317 -- A reference to P'Body_Version or P'Version is expanded to
2320 -- pragma Import (C, Vnn, "uuuuT");
2322 -- Get_Version_String (Vnn)
2324 -- where uuuu is the unit name (dots replaced by double underscore)
2325 -- and T is B for the cases of Body_Version, or Version applied to a
2326 -- subprogram acting as its own spec, and S for Version applied to a
2327 -- subprogram spec or package. This sequence of code references the
2328 -- unsigned constant created in the main program by the binder.
2330 -- A special exception occurs for Standard, where the string returned
2331 -- is a copy of the library string in gnatvsn.ads.
2333 when Attribute_Body_Version | Attribute_Version => Version : declare
2334 E : constant Entity_Id := Make_Temporary (Loc, 'V');
2339 -- If not library unit, get to containing library unit
2341 Pent := Entity (Pref);
2342 while Pent /= Standard_Standard
2343 and then Scope (Pent) /= Standard_Standard
2344 and then not Is_Child_Unit (Pent)
2346 Pent := Scope (Pent);
2349 -- Special case Standard and Standard.ASCII
2351 if Pent = Standard_Standard or else Pent = Standard_ASCII then
2353 Make_String_Literal (Loc,
2354 Strval => Verbose_Library_Version));
2359 -- Build required string constant
2361 Get_Name_String (Get_Unit_Name (Pent));
2364 for J in 1 .. Name_Len - 2 loop
2365 if Name_Buffer (J) = '.' then
2366 Store_String_Chars ("__");
2368 Store_String_Char (Get_Char_Code (Name_Buffer (J)));
2372 -- Case of subprogram acting as its own spec, always use body
2374 if Nkind (Declaration_Node (Pent)) in N_Subprogram_Specification
2375 and then Nkind (Parent (Declaration_Node (Pent))) =
2377 and then Acts_As_Spec (Parent (Declaration_Node (Pent)))
2379 Store_String_Chars ("B");
2381 -- Case of no body present, always use spec
2383 elsif not Unit_Requires_Body (Pent) then
2384 Store_String_Chars ("S");
2386 -- Otherwise use B for Body_Version, S for spec
2388 elsif Id = Attribute_Body_Version then
2389 Store_String_Chars ("B");
2391 Store_String_Chars ("S");
2395 Lib.Version_Referenced (S);
2397 -- Insert the object declaration
2399 Insert_Actions (N, New_List (
2400 Make_Object_Declaration (Loc,
2401 Defining_Identifier => E,
2402 Object_Definition =>
2403 New_Occurrence_Of (RTE (RE_Unsigned), Loc))));
2405 -- Set entity as imported with correct external name
2407 Set_Is_Imported (E);
2408 Set_Interface_Name (E, Make_String_Literal (Loc, S));
2410 -- Set entity as internal to ensure proper Sprint output of its
2411 -- implicit importation.
2413 Set_Is_Internal (E);
2415 -- And now rewrite original reference
2418 Make_Function_Call (Loc,
2419 Name => New_Occurrence_Of (RTE (RE_Get_Version_String), Loc),
2420 Parameter_Associations => New_List (
2421 New_Occurrence_Of (E, Loc))));
2424 Analyze_And_Resolve (N, RTE (RE_Version_String));
2431 -- Transforms 'Ceiling into a call to the floating-point attribute
2432 -- function Ceiling in Fat_xxx (where xxx is the root type)
2434 when Attribute_Ceiling =>
2435 Expand_Fpt_Attribute_R (N);
2441 -- Transforms 'Callable attribute into a call to the Callable function
2443 when Attribute_Callable => Callable :
2445 -- We have an object of a task interface class-wide type as a prefix
2446 -- to Callable. Generate:
2447 -- callable (Task_Id (Pref._disp_get_task_id));
2449 if Ada_Version >= Ada_2005
2450 and then Ekind (Ptyp) = E_Class_Wide_Type
2451 and then Is_Interface (Ptyp)
2452 and then Is_Task_Interface (Ptyp)
2455 Make_Function_Call (Loc,
2457 New_Occurrence_Of (RTE (RE_Callable), Loc),
2458 Parameter_Associations => New_List (
2459 Make_Unchecked_Type_Conversion (Loc,
2461 New_Occurrence_Of (RTE (RO_ST_Task_Id), Loc),
2463 Make_Selected_Component (Loc,
2465 New_Copy_Tree (Pref),
2467 Make_Identifier (Loc, Name_uDisp_Get_Task_Id))))));
2471 Build_Call_With_Task (Pref, RTE (RE_Callable)));
2474 Analyze_And_Resolve (N, Standard_Boolean);
2481 -- Transforms 'Caller attribute into a call to either the
2482 -- Task_Entry_Caller or the Protected_Entry_Caller function.
2484 when Attribute_Caller => Caller : declare
2485 Id_Kind : constant Entity_Id := RTE (RO_AT_Task_Id);
2486 Ent : constant Entity_Id := Entity (Pref);
2487 Conctype : constant Entity_Id := Scope (Ent);
2488 Nest_Depth : Integer := 0;
2495 if Is_Protected_Type (Conctype) then
2496 case Corresponding_Runtime_Package (Conctype) is
2497 when System_Tasking_Protected_Objects_Entries =>
2500 (RTE (RE_Protected_Entry_Caller), Loc);
2502 when System_Tasking_Protected_Objects_Single_Entry =>
2505 (RTE (RE_Protected_Single_Entry_Caller), Loc);
2508 raise Program_Error;
2512 Unchecked_Convert_To (Id_Kind,
2513 Make_Function_Call (Loc,
2515 Parameter_Associations => New_List (
2517 (Find_Protection_Object (Current_Scope), Loc)))));
2522 -- Determine the nesting depth of the E'Caller attribute, that
2523 -- is, how many accept statements are nested within the accept
2524 -- statement for E at the point of E'Caller. The runtime uses
2525 -- this depth to find the specified entry call.
2527 for J in reverse 0 .. Scope_Stack.Last loop
2528 S := Scope_Stack.Table (J).Entity;
2530 -- We should not reach the scope of the entry, as it should
2531 -- already have been checked in Sem_Attr that this attribute
2532 -- reference is within a matching accept statement.
2534 pragma Assert (S /= Conctype);
2539 elsif Is_Entry (S) then
2540 Nest_Depth := Nest_Depth + 1;
2545 Unchecked_Convert_To (Id_Kind,
2546 Make_Function_Call (Loc,
2548 New_Occurrence_Of (RTE (RE_Task_Entry_Caller), Loc),
2549 Parameter_Associations => New_List (
2550 Make_Integer_Literal (Loc,
2551 Intval => Int (Nest_Depth))))));
2554 Analyze_And_Resolve (N, Id_Kind);
2561 -- Transforms 'Compose into a call to the floating-point attribute
2562 -- function Compose in Fat_xxx (where xxx is the root type)
2564 -- Note: we strictly should have special code here to deal with the
2565 -- case of absurdly negative arguments (less than Integer'First)
2566 -- which will return a (signed) zero value, but it hardly seems
2567 -- worth the effort. Absurdly large positive arguments will raise
2568 -- constraint error which is fine.
2570 when Attribute_Compose =>
2571 Expand_Fpt_Attribute_RI (N);
2577 when Attribute_Constrained => Constrained : declare
2578 Formal_Ent : constant Entity_Id := Param_Entity (Pref);
2580 function Is_Constrained_Aliased_View (Obj : Node_Id) return Boolean;
2581 -- Ada 2005 (AI-363): Returns True if the object name Obj denotes a
2582 -- view of an aliased object whose subtype is constrained.
2584 ---------------------------------
2585 -- Is_Constrained_Aliased_View --
2586 ---------------------------------
2588 function Is_Constrained_Aliased_View (Obj : Node_Id) return Boolean is
2592 if Is_Entity_Name (Obj) then
2595 if Present (Renamed_Object (E)) then
2596 return Is_Constrained_Aliased_View (Renamed_Object (E));
2598 return Is_Aliased (E) and then Is_Constrained (Etype (E));
2602 return Is_Aliased_View (Obj)
2604 (Is_Constrained (Etype (Obj))
2606 (Nkind (Obj) = N_Explicit_Dereference
2608 not Object_Type_Has_Constrained_Partial_View
2609 (Typ => Base_Type (Etype (Obj)),
2610 Scop => Current_Scope)));
2612 end Is_Constrained_Aliased_View;
2614 -- Start of processing for Constrained
2617 -- Reference to a parameter where the value is passed as an extra
2618 -- actual, corresponding to the extra formal referenced by the
2619 -- Extra_Constrained field of the corresponding formal. If this
2620 -- is an entry in-parameter, it is replaced by a constant renaming
2621 -- for which Extra_Constrained is never created.
2623 if Present (Formal_Ent)
2624 and then Ekind (Formal_Ent) /= E_Constant
2625 and then Present (Extra_Constrained (Formal_Ent))
2629 (Extra_Constrained (Formal_Ent), Sloc (N)));
2631 -- For variables with a Extra_Constrained field, we use the
2632 -- corresponding entity.
2634 elsif Nkind (Pref) = N_Identifier
2635 and then Ekind (Entity (Pref)) = E_Variable
2636 and then Present (Extra_Constrained (Entity (Pref)))
2640 (Extra_Constrained (Entity (Pref)), Sloc (N)));
2642 -- For all other entity names, we can tell at compile time
2644 elsif Is_Entity_Name (Pref) then
2646 Ent : constant Entity_Id := Entity (Pref);
2650 -- (RM J.4) obsolescent cases
2652 if Is_Type (Ent) then
2656 if Is_Private_Type (Ent) then
2657 Res := not Has_Discriminants (Ent)
2658 or else Is_Constrained (Ent);
2660 -- It not a private type, must be a generic actual type
2661 -- that corresponded to a private type. We know that this
2662 -- correspondence holds, since otherwise the reference
2663 -- within the generic template would have been illegal.
2666 if Is_Composite_Type (Underlying_Type (Ent)) then
2667 Res := Is_Constrained (Ent);
2673 -- If the prefix is not a variable or is aliased, then
2674 -- definitely true; if it's a formal parameter without an
2675 -- associated extra formal, then treat it as constrained.
2677 -- Ada 2005 (AI-363): An aliased prefix must be known to be
2678 -- constrained in order to set the attribute to True.
2680 elsif not Is_Variable (Pref)
2681 or else Present (Formal_Ent)
2682 or else (Ada_Version < Ada_2005
2683 and then Is_Aliased_View (Pref))
2684 or else (Ada_Version >= Ada_2005
2685 and then Is_Constrained_Aliased_View (Pref))
2689 -- Variable case, look at type to see if it is constrained.
2690 -- Note that the one case where this is not accurate (the
2691 -- procedure formal case), has been handled above.
2693 -- We use the Underlying_Type here (and below) in case the
2694 -- type is private without discriminants, but the full type
2695 -- has discriminants. This case is illegal, but we generate it
2696 -- internally for passing to the Extra_Constrained parameter.
2699 -- In Ada 2012, test for case of a limited tagged type, in
2700 -- which case the attribute is always required to return
2701 -- True. The underlying type is tested, to make sure we also
2702 -- return True for cases where there is an unconstrained
2703 -- object with an untagged limited partial view which has
2704 -- defaulted discriminants (such objects always produce a
2705 -- False in earlier versions of Ada). (Ada 2012: AI05-0214)
2707 Res := Is_Constrained (Underlying_Type (Etype (Ent)))
2709 (Ada_Version >= Ada_2012
2710 and then Is_Tagged_Type (Underlying_Type (Ptyp))
2711 and then Is_Limited_Type (Ptyp));
2714 Rewrite (N, New_Occurrence_Of (Boolean_Literals (Res), Loc));
2717 -- Prefix is not an entity name. These are also cases where we can
2718 -- always tell at compile time by looking at the form and type of the
2719 -- prefix. If an explicit dereference of an object with constrained
2720 -- partial view, this is unconstrained (Ada 2005: AI95-0363). If the
2721 -- underlying type is a limited tagged type, then Constrained is
2722 -- required to always return True (Ada 2012: AI05-0214).
2728 not Is_Variable (Pref)
2730 (Nkind (Pref) = N_Explicit_Dereference
2732 not Object_Type_Has_Constrained_Partial_View
2733 (Typ => Base_Type (Ptyp),
2734 Scop => Current_Scope))
2735 or else Is_Constrained (Underlying_Type (Ptyp))
2736 or else (Ada_Version >= Ada_2012
2737 and then Is_Tagged_Type (Underlying_Type (Ptyp))
2738 and then Is_Limited_Type (Ptyp))),
2742 Analyze_And_Resolve (N, Standard_Boolean);
2749 -- Transforms 'Copy_Sign into a call to the floating-point attribute
2750 -- function Copy_Sign in Fat_xxx (where xxx is the root type)
2752 when Attribute_Copy_Sign =>
2753 Expand_Fpt_Attribute_RR (N);
2759 -- Transforms 'Count attribute into a call to the Count function
2761 when Attribute_Count => Count : declare
2763 Conctyp : Entity_Id;
2765 Entry_Id : Entity_Id;
2770 -- If the prefix is a member of an entry family, retrieve both
2771 -- entry name and index. For a simple entry there is no index.
2773 if Nkind (Pref) = N_Indexed_Component then
2774 Entnam := Prefix (Pref);
2775 Index := First (Expressions (Pref));
2781 Entry_Id := Entity (Entnam);
2783 -- Find the concurrent type in which this attribute is referenced
2784 -- (there had better be one).
2786 Conctyp := Current_Scope;
2787 while not Is_Concurrent_Type (Conctyp) loop
2788 Conctyp := Scope (Conctyp);
2793 if Is_Protected_Type (Conctyp) then
2794 case Corresponding_Runtime_Package (Conctyp) is
2795 when System_Tasking_Protected_Objects_Entries =>
2796 Name := New_Occurrence_Of (RTE (RE_Protected_Count), Loc);
2799 Make_Function_Call (Loc,
2801 Parameter_Associations => New_List (
2803 (Find_Protection_Object (Current_Scope), Loc),
2804 Entry_Index_Expression
2805 (Loc, Entry_Id, Index, Scope (Entry_Id))));
2807 when System_Tasking_Protected_Objects_Single_Entry =>
2809 New_Occurrence_Of (RTE (RE_Protected_Count_Entry), Loc);
2812 Make_Function_Call (Loc,
2814 Parameter_Associations => New_List (
2816 (Find_Protection_Object (Current_Scope), Loc)));
2819 raise Program_Error;
2826 Make_Function_Call (Loc,
2827 Name => New_Occurrence_Of (RTE (RE_Task_Count), Loc),
2828 Parameter_Associations => New_List (
2829 Entry_Index_Expression (Loc,
2830 Entry_Id, Index, Scope (Entry_Id))));
2833 -- The call returns type Natural but the context is universal integer
2834 -- so any integer type is allowed. The attribute was already resolved
2835 -- so its Etype is the required result type. If the base type of the
2836 -- context type is other than Standard.Integer we put in a conversion
2837 -- to the required type. This can be a normal typed conversion since
2838 -- both input and output types of the conversion are integer types
2840 if Base_Type (Typ) /= Base_Type (Standard_Integer) then
2841 Rewrite (N, Convert_To (Typ, Call));
2846 Analyze_And_Resolve (N, Typ);
2849 ---------------------
2850 -- Descriptor_Size --
2851 ---------------------
2853 when Attribute_Descriptor_Size =>
2855 -- Attribute Descriptor_Size is handled by the back end when applied
2856 -- to an unconstrained array type.
2858 if Is_Array_Type (Ptyp)
2859 and then not Is_Constrained (Ptyp)
2861 Apply_Universal_Integer_Attribute_Checks (N);
2863 -- For any other type, the descriptor size is 0 because there is no
2864 -- actual descriptor, but the result is not formally static.
2867 Rewrite (N, Make_Integer_Literal (Loc, 0));
2869 Set_Is_Static_Expression (N, False);
2876 -- This processing is shared by Elab_Spec
2878 -- What we do is to insert the following declarations
2881 -- pragma Import (C, enn, "name___elabb/s");
2883 -- and then the Elab_Body/Spec attribute is replaced by a reference
2884 -- to this defining identifier.
2886 when Attribute_Elab_Body |
2887 Attribute_Elab_Spec =>
2889 -- Leave attribute unexpanded in CodePeer mode: the gnat2scil
2890 -- back-end knows how to handle these attributes directly.
2892 if CodePeer_Mode then
2897 Ent : constant Entity_Id := Make_Temporary (Loc, 'E');
2901 procedure Make_Elab_String (Nod : Node_Id);
2902 -- Given Nod, an identifier, or a selected component, put the
2903 -- image into the current string literal, with double underline
2904 -- between components.
2906 ----------------------
2907 -- Make_Elab_String --
2908 ----------------------
2910 procedure Make_Elab_String (Nod : Node_Id) is
2912 if Nkind (Nod) = N_Selected_Component then
2913 Make_Elab_String (Prefix (Nod));
2914 Store_String_Char ('_');
2915 Store_String_Char ('_');
2916 Get_Name_String (Chars (Selector_Name (Nod)));
2919 pragma Assert (Nkind (Nod) = N_Identifier);
2920 Get_Name_String (Chars (Nod));
2923 Store_String_Chars (Name_Buffer (1 .. Name_Len));
2924 end Make_Elab_String;
2926 -- Start of processing for Elab_Body/Elab_Spec
2929 -- First we need to prepare the string literal for the name of
2930 -- the elaboration routine to be referenced.
2933 Make_Elab_String (Pref);
2934 Store_String_Chars ("___elab");
2935 Lang := Make_Identifier (Loc, Name_C);
2937 if Id = Attribute_Elab_Body then
2938 Store_String_Char ('b');
2940 Store_String_Char ('s');
2945 Insert_Actions (N, New_List (
2946 Make_Subprogram_Declaration (Loc,
2948 Make_Procedure_Specification (Loc,
2949 Defining_Unit_Name => Ent)),
2952 Chars => Name_Import,
2953 Pragma_Argument_Associations => New_List (
2954 Make_Pragma_Argument_Association (Loc, Expression => Lang),
2956 Make_Pragma_Argument_Association (Loc,
2957 Expression => Make_Identifier (Loc, Chars (Ent))),
2959 Make_Pragma_Argument_Association (Loc,
2960 Expression => Make_String_Literal (Loc, Str))))));
2962 Set_Entity (N, Ent);
2963 Rewrite (N, New_Occurrence_Of (Ent, Loc));
2966 --------------------
2967 -- Elab_Subp_Body --
2968 --------------------
2970 -- Always ignored. In CodePeer mode, gnat2scil knows how to handle
2971 -- this attribute directly, and if we are not in CodePeer mode it is
2972 -- entirely ignored ???
2974 when Attribute_Elab_Subp_Body =>
2981 -- Elaborated is always True for preelaborated units, predefined units,
2982 -- pure units and units which have Elaborate_Body pragmas. These units
2983 -- have no elaboration entity.
2985 -- Note: The Elaborated attribute is never passed to the back end
2987 when Attribute_Elaborated => Elaborated : declare
2988 Ent : constant Entity_Id := Entity (Pref);
2991 if Present (Elaboration_Entity (Ent)) then
2995 New_Occurrence_Of (Elaboration_Entity (Ent), Loc),
2997 Make_Integer_Literal (Loc, Uint_0)));
2998 Analyze_And_Resolve (N, Typ);
3000 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
3008 when Attribute_Enum_Rep => Enum_Rep :
3010 -- X'Enum_Rep (Y) expands to
3014 -- This is simply a direct conversion from the enumeration type to
3015 -- the target integer type, which is treated by the back end as a
3016 -- normal integer conversion, treating the enumeration type as an
3017 -- integer, which is exactly what we want. We set Conversion_OK to
3018 -- make sure that the analyzer does not complain about what otherwise
3019 -- might be an illegal conversion.
3021 if Is_Non_Empty_List (Exprs) then
3023 OK_Convert_To (Typ, Relocate_Node (First (Exprs))));
3025 -- X'Enum_Rep where X is an enumeration literal is replaced by
3026 -- the literal value.
3028 elsif Ekind (Entity (Pref)) = E_Enumeration_Literal then
3030 Make_Integer_Literal (Loc, Enumeration_Rep (Entity (Pref))));
3032 -- If this is a renaming of a literal, recover the representation
3033 -- of the original. If it renames an expression there is nothing
3036 elsif Ekind (Entity (Pref)) = E_Constant
3037 and then Present (Renamed_Object (Entity (Pref)))
3038 and then Is_Entity_Name (Renamed_Object (Entity (Pref)))
3039 and then Ekind (Entity (Renamed_Object (Entity (Pref)))) =
3040 E_Enumeration_Literal
3043 Make_Integer_Literal (Loc,
3044 Enumeration_Rep (Entity (Renamed_Object (Entity (Pref))))));
3046 -- X'Enum_Rep where X is an object does a direct unchecked conversion
3047 -- of the object value, as described for the type case above.
3051 OK_Convert_To (Typ, Relocate_Node (Pref)));
3055 Analyze_And_Resolve (N, Typ);
3062 when Attribute_Enum_Val => Enum_Val : declare
3064 Btyp : constant Entity_Id := Base_Type (Ptyp);
3067 -- X'Enum_Val (Y) expands to
3069 -- [constraint_error when _rep_to_pos (Y, False) = -1, msg]
3072 Expr := Unchecked_Convert_To (Ptyp, First (Exprs));
3075 Make_Raise_Constraint_Error (Loc,
3079 Make_Function_Call (Loc,
3081 New_Occurrence_Of (TSS (Btyp, TSS_Rep_To_Pos), Loc),
3082 Parameter_Associations => New_List (
3083 Relocate_Node (Duplicate_Subexpr (Expr)),
3084 New_Occurrence_Of (Standard_False, Loc))),
3086 Right_Opnd => Make_Integer_Literal (Loc, -1)),
3087 Reason => CE_Range_Check_Failed));
3090 Analyze_And_Resolve (N, Ptyp);
3097 -- Transforms 'Exponent into a call to the floating-point attribute
3098 -- function Exponent in Fat_xxx (where xxx is the root type)
3100 when Attribute_Exponent =>
3101 Expand_Fpt_Attribute_R (N);
3107 -- transforme X'External_Tag into Ada.Tags.External_Tag (X'tag)
3109 when Attribute_External_Tag => External_Tag :
3112 Make_Function_Call (Loc,
3113 Name => New_Occurrence_Of (RTE (RE_External_Tag), Loc),
3114 Parameter_Associations => New_List (
3115 Make_Attribute_Reference (Loc,
3116 Attribute_Name => Name_Tag,
3117 Prefix => Prefix (N)))));
3119 Analyze_And_Resolve (N, Standard_String);
3126 when Attribute_First =>
3128 -- If the prefix type is a constrained packed array type which
3129 -- already has a Packed_Array_Impl_Type representation defined, then
3130 -- replace this attribute with a direct reference to 'First of the
3131 -- appropriate index subtype (since otherwise the back end will try
3132 -- to give us the value of 'First for this implementation type).
3134 if Is_Constrained_Packed_Array (Ptyp) then
3136 Make_Attribute_Reference (Loc,
3137 Attribute_Name => Name_First,
3139 New_Occurrence_Of (Get_Index_Subtype (N), Loc)));
3140 Analyze_And_Resolve (N, Typ);
3142 -- For access type, apply access check as needed
3144 elsif Is_Access_Type (Ptyp) then
3145 Apply_Access_Check (N);
3147 -- For scalar type, if low bound is a reference to an entity, just
3148 -- replace with a direct reference. Note that we can only have a
3149 -- reference to a constant entity at this stage, anything else would
3150 -- have already been rewritten.
3152 elsif Is_Scalar_Type (Ptyp) then
3154 Lo : constant Node_Id := Type_Low_Bound (Ptyp);
3156 if Is_Entity_Name (Lo) then
3157 Rewrite (N, New_Occurrence_Of (Entity (Lo), Loc));
3166 -- Compute this if component clause was present, otherwise we leave the
3167 -- computation to be completed in the back-end, since we don't know what
3168 -- layout will be chosen.
3170 when Attribute_First_Bit => First_Bit_Attr : declare
3171 CE : constant Entity_Id := Entity (Selector_Name (Pref));
3174 -- In Ada 2005 (or later) if we have the non-default bit order, then
3175 -- we return the original value as given in the component clause
3176 -- (RM 2005 13.5.2(3/2)).
3178 if Present (Component_Clause (CE))
3179 and then Ada_Version >= Ada_2005
3180 and then Reverse_Bit_Order (Scope (CE))
3183 Make_Integer_Literal (Loc,
3184 Intval => Expr_Value (First_Bit (Component_Clause (CE)))));
3185 Analyze_And_Resolve (N, Typ);
3187 -- Otherwise (Ada 83/95 or Ada 2005 or later with default bit order),
3188 -- rewrite with normalized value if we know it statically.
3190 elsif Known_Static_Component_Bit_Offset (CE) then
3192 Make_Integer_Literal (Loc,
3193 Component_Bit_Offset (CE) mod System_Storage_Unit));
3194 Analyze_And_Resolve (N, Typ);
3196 -- Otherwise left to back end, just do universal integer checks
3199 Apply_Universal_Integer_Attribute_Checks (N);
3209 -- fixtype'Fixed_Value (integer-value)
3213 -- fixtype(integer-value)
3215 -- We do all the required analysis of the conversion here, because we do
3216 -- not want this to go through the fixed-point conversion circuits. Note
3217 -- that the back end always treats fixed-point as equivalent to the
3218 -- corresponding integer type anyway.
3220 when Attribute_Fixed_Value => Fixed_Value :
3223 Make_Type_Conversion (Loc,
3224 Subtype_Mark => New_Occurrence_Of (Entity (Pref), Loc),
3225 Expression => Relocate_Node (First (Exprs))));
3226 Set_Etype (N, Entity (Pref));
3229 -- Note: it might appear that a properly analyzed unchecked conversion
3230 -- would be just fine here, but that's not the case, since the full
3231 -- range checks performed by the following call are critical.
3233 Apply_Type_Conversion_Checks (N);
3240 -- Transforms 'Floor into a call to the floating-point attribute
3241 -- function Floor in Fat_xxx (where xxx is the root type)
3243 when Attribute_Floor =>
3244 Expand_Fpt_Attribute_R (N);
3250 -- For the fixed-point type Typ:
3256 -- Result_Type (System.Fore (Universal_Real (Type'First)),
3257 -- Universal_Real (Type'Last))
3259 -- Note that we know that the type is a non-static subtype, or Fore
3260 -- would have itself been computed dynamically in Eval_Attribute.
3262 when Attribute_Fore => Fore : begin
3265 Make_Function_Call (Loc,
3266 Name => New_Occurrence_Of (RTE (RE_Fore), Loc),
3268 Parameter_Associations => New_List (
3269 Convert_To (Universal_Real,
3270 Make_Attribute_Reference (Loc,
3271 Prefix => New_Occurrence_Of (Ptyp, Loc),
3272 Attribute_Name => Name_First)),
3274 Convert_To (Universal_Real,
3275 Make_Attribute_Reference (Loc,
3276 Prefix => New_Occurrence_Of (Ptyp, Loc),
3277 Attribute_Name => Name_Last))))));
3279 Analyze_And_Resolve (N, Typ);
3286 -- Transforms 'Fraction into a call to the floating-point attribute
3287 -- function Fraction in Fat_xxx (where xxx is the root type)
3289 when Attribute_Fraction =>
3290 Expand_Fpt_Attribute_R (N);
3296 when Attribute_From_Any => From_Any : declare
3297 P_Type : constant Entity_Id := Etype (Pref);
3298 Decls : constant List_Id := New_List;
3301 Build_From_Any_Call (P_Type,
3302 Relocate_Node (First (Exprs)),
3304 Insert_Actions (N, Decls);
3305 Analyze_And_Resolve (N, P_Type);
3308 ----------------------
3309 -- Has_Same_Storage --
3310 ----------------------
3312 when Attribute_Has_Same_Storage => Has_Same_Storage : declare
3313 Loc : constant Source_Ptr := Sloc (N);
3315 X : constant Node_Id := Prefix (N);
3316 Y : constant Node_Id := First (Expressions (N));
3319 X_Addr, Y_Addr : Node_Id;
3320 -- Rhe expressions for their addresses
3322 X_Size, Y_Size : Node_Id;
3323 -- Rhe expressions for their sizes
3326 -- The attribute is expanded as:
3328 -- (X'address = Y'address)
3329 -- and then (X'Size = Y'Size)
3331 -- If both arguments have the same Etype the second conjunct can be
3335 Make_Attribute_Reference (Loc,
3336 Attribute_Name => Name_Address,
3337 Prefix => New_Copy_Tree (X));
3340 Make_Attribute_Reference (Loc,
3341 Attribute_Name => Name_Address,
3342 Prefix => New_Copy_Tree (Y));
3345 Make_Attribute_Reference (Loc,
3346 Attribute_Name => Name_Size,
3347 Prefix => New_Copy_Tree (X));
3350 Make_Attribute_Reference (Loc,
3351 Attribute_Name => Name_Size,
3352 Prefix => New_Copy_Tree (Y));
3354 if Etype (X) = Etype (Y) then
3357 Left_Opnd => X_Addr,
3358 Right_Opnd => Y_Addr)));
3364 Left_Opnd => X_Addr,
3365 Right_Opnd => Y_Addr),
3368 Left_Opnd => X_Size,
3369 Right_Opnd => Y_Size)));
3372 Analyze_And_Resolve (N, Standard_Boolean);
3373 end Has_Same_Storage;
3379 -- For an exception returns a reference to the exception data:
3380 -- Exception_Id!(Prefix'Reference)
3382 -- For a task it returns a reference to the _task_id component of
3383 -- corresponding record:
3385 -- taskV!(Prefix)._Task_Id, converted to the type Task_Id defined
3387 -- in Ada.Task_Identification
3389 when Attribute_Identity => Identity : declare
3390 Id_Kind : Entity_Id;
3393 if Ptyp = Standard_Exception_Type then
3394 Id_Kind := RTE (RE_Exception_Id);
3396 if Present (Renamed_Object (Entity (Pref))) then
3397 Set_Entity (Pref, Renamed_Object (Entity (Pref)));
3401 Unchecked_Convert_To (Id_Kind, Make_Reference (Loc, Pref)));
3403 Id_Kind := RTE (RO_AT_Task_Id);
3405 -- If the prefix is a task interface, the Task_Id is obtained
3406 -- dynamically through a dispatching call, as for other task
3407 -- attributes applied to interfaces.
3409 if Ada_Version >= Ada_2005
3410 and then Ekind (Ptyp) = E_Class_Wide_Type
3411 and then Is_Interface (Ptyp)
3412 and then Is_Task_Interface (Ptyp)
3415 Unchecked_Convert_To (Id_Kind,
3416 Make_Selected_Component (Loc,
3418 New_Copy_Tree (Pref),
3420 Make_Identifier (Loc, Name_uDisp_Get_Task_Id))));
3424 Unchecked_Convert_To (Id_Kind, Concurrent_Ref (Pref)));
3428 Analyze_And_Resolve (N, Id_Kind);
3435 -- Image attribute is handled in separate unit Exp_Imgv
3437 when Attribute_Image =>
3438 Exp_Imgv.Expand_Image_Attribute (N);
3444 -- X'Img is expanded to typ'Image (X), where typ is the type of X
3446 when Attribute_Img => Img :
3449 Make_Attribute_Reference (Loc,
3450 Prefix => New_Occurrence_Of (Ptyp, Loc),
3451 Attribute_Name => Name_Image,
3452 Expressions => New_List (Relocate_Node (Pref))));
3454 Analyze_And_Resolve (N, Standard_String);
3461 when Attribute_Input => Input : declare
3462 P_Type : constant Entity_Id := Entity (Pref);
3463 B_Type : constant Entity_Id := Base_Type (P_Type);
3464 U_Type : constant Entity_Id := Underlying_Type (P_Type);
3465 Strm : constant Node_Id := First (Exprs);
3473 Cntrl : Node_Id := Empty;
3474 -- Value for controlling argument in call. Always Empty except in
3475 -- the dispatching (class-wide type) case, where it is a reference
3476 -- to the dummy object initialized to the right internal tag.
3478 procedure Freeze_Stream_Subprogram (F : Entity_Id);
3479 -- The expansion of the attribute reference may generate a call to
3480 -- a user-defined stream subprogram that is frozen by the call. This
3481 -- can lead to access-before-elaboration problem if the reference
3482 -- appears in an object declaration and the subprogram body has not
3483 -- been seen. The freezing of the subprogram requires special code
3484 -- because it appears in an expanded context where expressions do
3485 -- not freeze their constituents.
3487 ------------------------------
3488 -- Freeze_Stream_Subprogram --
3489 ------------------------------
3491 procedure Freeze_Stream_Subprogram (F : Entity_Id) is
3492 Decl : constant Node_Id := Unit_Declaration_Node (F);
3496 -- If this is user-defined subprogram, the corresponding
3497 -- stream function appears as a renaming-as-body, and the
3498 -- user subprogram must be retrieved by tree traversal.
3501 and then Nkind (Decl) = N_Subprogram_Declaration
3502 and then Present (Corresponding_Body (Decl))
3504 Bod := Corresponding_Body (Decl);
3506 if Nkind (Unit_Declaration_Node (Bod)) =
3507 N_Subprogram_Renaming_Declaration
3509 Set_Is_Frozen (Entity (Name (Unit_Declaration_Node (Bod))));
3512 end Freeze_Stream_Subprogram;
3514 -- Start of processing for Input
3517 -- If no underlying type, we have an error that will be diagnosed
3518 -- elsewhere, so here we just completely ignore the expansion.
3524 -- Stream operations can appear in user code even if the restriction
3525 -- No_Streams is active (for example, when instantiating a predefined
3526 -- container). In that case rewrite the attribute as a Raise to
3527 -- prevent any run-time use.
3529 if Restriction_Active (No_Streams) then
3531 Make_Raise_Program_Error (Sloc (N),
3532 Reason => PE_Stream_Operation_Not_Allowed));
3533 Set_Etype (N, B_Type);
3537 -- If there is a TSS for Input, just call it
3539 Fname := Find_Stream_Subprogram (P_Type, TSS_Stream_Input);
3541 if Present (Fname) then
3545 -- If there is a Stream_Convert pragma, use it, we rewrite
3547 -- sourcetyp'Input (stream)
3551 -- sourcetyp (streamread (strmtyp'Input (stream)));
3553 -- where streamread is the given Read function that converts an
3554 -- argument of type strmtyp to type sourcetyp or a type from which
3555 -- it is derived (extra conversion required for the derived case).
3557 Prag := Get_Stream_Convert_Pragma (P_Type);
3559 if Present (Prag) then
3560 Arg2 := Next (First (Pragma_Argument_Associations (Prag)));
3561 Rfunc := Entity (Expression (Arg2));
3565 Make_Function_Call (Loc,
3566 Name => New_Occurrence_Of (Rfunc, Loc),
3567 Parameter_Associations => New_List (
3568 Make_Attribute_Reference (Loc,
3571 (Etype (First_Formal (Rfunc)), Loc),
3572 Attribute_Name => Name_Input,
3573 Expressions => Exprs)))));
3575 Analyze_And_Resolve (N, B_Type);
3580 elsif Is_Elementary_Type (U_Type) then
3582 -- A special case arises if we have a defined _Read routine,
3583 -- since in this case we are required to call this routine.
3585 if Present (TSS (Base_Type (U_Type), TSS_Stream_Read)) then
3586 Build_Record_Or_Elementary_Input_Function
3587 (Loc, U_Type, Decl, Fname);
3588 Insert_Action (N, Decl);
3590 -- For normal cases, we call the I_xxx routine directly
3593 Rewrite (N, Build_Elementary_Input_Call (N));
3594 Analyze_And_Resolve (N, P_Type);
3600 elsif Is_Array_Type (U_Type) then
3601 Build_Array_Input_Function (Loc, U_Type, Decl, Fname);
3602 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
3604 -- Dispatching case with class-wide type
3606 elsif Is_Class_Wide_Type (P_Type) then
3608 -- No need to do anything else compiling under restriction
3609 -- No_Dispatching_Calls. During the semantic analysis we
3610 -- already notified such violation.
3612 if Restriction_Active (No_Dispatching_Calls) then
3617 Rtyp : constant Entity_Id := Root_Type (P_Type);
3621 -- Read the internal tag (RM 13.13.2(34)) and use it to
3622 -- initialize a dummy tag value:
3624 -- Descendant_Tag (String'Input (Strm), P_Type);
3626 -- This value is used only to provide a controlling
3627 -- argument for the eventual _Input call. Descendant_Tag is
3628 -- called rather than Internal_Tag to ensure that we have a
3629 -- tag for a type that is descended from the prefix type and
3630 -- declared at the same accessibility level (the exception
3631 -- Tag_Error will be raised otherwise). The level check is
3632 -- required for Ada 2005 because tagged types can be
3633 -- extended in nested scopes (AI-344).
3635 -- Note: we used to generate an explicit declaration of a
3636 -- constant Ada.Tags.Tag object, and use an occurrence of
3637 -- this constant in Cntrl, but this caused a secondary stack
3641 Make_Function_Call (Loc,
3643 New_Occurrence_Of (RTE (RE_Descendant_Tag), Loc),
3644 Parameter_Associations => New_List (
3645 Make_Attribute_Reference (Loc,
3647 New_Occurrence_Of (Standard_String, Loc),
3648 Attribute_Name => Name_Input,
3649 Expressions => New_List (
3650 Relocate_Node (Duplicate_Subexpr (Strm)))),
3651 Make_Attribute_Reference (Loc,
3652 Prefix => New_Occurrence_Of (P_Type, Loc),
3653 Attribute_Name => Name_Tag)));
3654 Set_Etype (Expr, RTE (RE_Tag));
3656 -- Now we need to get the entity for the call, and construct
3657 -- a function call node, where we preset a reference to Dnn
3658 -- as the controlling argument (doing an unchecked convert
3659 -- to the class-wide tagged type to make it look like a real
3662 Fname := Find_Prim_Op (Rtyp, TSS_Stream_Input);
3663 Cntrl := Unchecked_Convert_To (P_Type, Expr);
3664 Set_Etype (Cntrl, P_Type);
3665 Set_Parent (Cntrl, N);
3668 -- For tagged types, use the primitive Input function
3670 elsif Is_Tagged_Type (U_Type) then
3671 Fname := Find_Prim_Op (U_Type, TSS_Stream_Input);
3673 -- All other record type cases, including protected records. The
3674 -- latter only arise for expander generated code for handling
3675 -- shared passive partition access.
3679 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
3681 -- Ada 2005 (AI-216): Program_Error is raised executing default
3682 -- implementation of the Input attribute of an unchecked union
3683 -- type if the type lacks default discriminant values.
3685 if Is_Unchecked_Union (Base_Type (U_Type))
3686 and then No (Discriminant_Constraint (U_Type))
3689 Make_Raise_Program_Error (Loc,
3690 Reason => PE_Unchecked_Union_Restriction));
3695 -- Build the type's Input function, passing the subtype rather
3696 -- than its base type, because checks are needed in the case of
3697 -- constrained discriminants (see Ada 2012 AI05-0192).
3699 Build_Record_Or_Elementary_Input_Function
3700 (Loc, U_Type, Decl, Fname);
3701 Insert_Action (N, Decl);
3703 if Nkind (Parent (N)) = N_Object_Declaration
3704 and then Is_Record_Type (U_Type)
3706 -- The stream function may contain calls to user-defined
3707 -- Read procedures for individual components.
3714 Comp := First_Component (U_Type);
3715 while Present (Comp) loop
3717 Find_Stream_Subprogram
3718 (Etype (Comp), TSS_Stream_Read);
3720 if Present (Func) then
3721 Freeze_Stream_Subprogram (Func);
3724 Next_Component (Comp);
3731 -- If we fall through, Fname is the function to be called. The result
3732 -- is obtained by calling the appropriate function, then converting
3733 -- the result. The conversion does a subtype check.
3736 Make_Function_Call (Loc,
3737 Name => New_Occurrence_Of (Fname, Loc),
3738 Parameter_Associations => New_List (
3739 Relocate_Node (Strm)));
3741 Set_Controlling_Argument (Call, Cntrl);
3742 Rewrite (N, Unchecked_Convert_To (P_Type, Call));
3743 Analyze_And_Resolve (N, P_Type);
3745 if Nkind (Parent (N)) = N_Object_Declaration then
3746 Freeze_Stream_Subprogram (Fname);
3756 -- inttype'Fixed_Value (fixed-value)
3760 -- inttype(integer-value))
3762 -- we do all the required analysis of the conversion here, because we do
3763 -- not want this to go through the fixed-point conversion circuits. Note
3764 -- that the back end always treats fixed-point as equivalent to the
3765 -- corresponding integer type anyway.
3767 when Attribute_Integer_Value => Integer_Value :
3770 Make_Type_Conversion (Loc,
3771 Subtype_Mark => New_Occurrence_Of (Entity (Pref), Loc),
3772 Expression => Relocate_Node (First (Exprs))));
3773 Set_Etype (N, Entity (Pref));
3776 -- Note: it might appear that a properly analyzed unchecked conversion
3777 -- would be just fine here, but that's not the case, since the full
3778 -- range checks performed by the following call are critical.
3780 Apply_Type_Conversion_Checks (N);
3787 when Attribute_Invalid_Value =>
3788 Rewrite (N, Get_Simple_Init_Val (Ptyp, N));
3794 when Attribute_Last =>
3796 -- If the prefix type is a constrained packed array type which
3797 -- already has a Packed_Array_Impl_Type representation defined, then
3798 -- replace this attribute with a direct reference to 'Last of the
3799 -- appropriate index subtype (since otherwise the back end will try
3800 -- to give us the value of 'Last for this implementation type).
3802 if Is_Constrained_Packed_Array (Ptyp) then
3804 Make_Attribute_Reference (Loc,
3805 Attribute_Name => Name_Last,
3806 Prefix => New_Occurrence_Of (Get_Index_Subtype (N), Loc)));
3807 Analyze_And_Resolve (N, Typ);
3809 -- For access type, apply access check as needed
3811 elsif Is_Access_Type (Ptyp) then
3812 Apply_Access_Check (N);
3814 -- For scalar type, if low bound is a reference to an entity, just
3815 -- replace with a direct reference. Note that we can only have a
3816 -- reference to a constant entity at this stage, anything else would
3817 -- have already been rewritten.
3819 elsif Is_Scalar_Type (Ptyp) then
3821 Hi : constant Node_Id := Type_High_Bound (Ptyp);
3823 if Is_Entity_Name (Hi) then
3824 Rewrite (N, New_Occurrence_Of (Entity (Hi), Loc));
3833 -- We compute this if a component clause was present, otherwise we leave
3834 -- the computation up to the back end, since we don't know what layout
3837 when Attribute_Last_Bit => Last_Bit_Attr : declare
3838 CE : constant Entity_Id := Entity (Selector_Name (Pref));
3841 -- In Ada 2005 (or later) if we have the non-default bit order, then
3842 -- we return the original value as given in the component clause
3843 -- (RM 2005 13.5.2(3/2)).
3845 if Present (Component_Clause (CE))
3846 and then Ada_Version >= Ada_2005
3847 and then Reverse_Bit_Order (Scope (CE))
3850 Make_Integer_Literal (Loc,
3851 Intval => Expr_Value (Last_Bit (Component_Clause (CE)))));
3852 Analyze_And_Resolve (N, Typ);
3854 -- Otherwise (Ada 83/95 or Ada 2005 or later with default bit order),
3855 -- rewrite with normalized value if we know it statically.
3857 elsif Known_Static_Component_Bit_Offset (CE)
3858 and then Known_Static_Esize (CE)
3861 Make_Integer_Literal (Loc,
3862 Intval => (Component_Bit_Offset (CE) mod System_Storage_Unit)
3864 Analyze_And_Resolve (N, Typ);
3866 -- Otherwise leave to back end, just apply universal integer checks
3869 Apply_Universal_Integer_Attribute_Checks (N);
3877 -- Transforms 'Leading_Part into a call to the floating-point attribute
3878 -- function Leading_Part in Fat_xxx (where xxx is the root type)
3880 -- Note: strictly, we should generate special case code to deal with
3881 -- absurdly large positive arguments (greater than Integer'Last), which
3882 -- result in returning the first argument unchanged, but it hardly seems
3883 -- worth the effort. We raise constraint error for absurdly negative
3884 -- arguments which is fine.
3886 when Attribute_Leading_Part =>
3887 Expand_Fpt_Attribute_RI (N);
3893 when Attribute_Length => Length : declare
3898 -- Processing for packed array types
3900 if Is_Array_Type (Ptyp) and then Is_Packed (Ptyp) then
3901 Ityp := Get_Index_Subtype (N);
3903 -- If the index type, Ityp, is an enumeration type with holes,
3904 -- then we calculate X'Length explicitly using
3907 -- (0, Ityp'Pos (X'Last (N)) -
3908 -- Ityp'Pos (X'First (N)) + 1);
3910 -- Since the bounds in the template are the representation values
3911 -- and the back end would get the wrong value.
3913 if Is_Enumeration_Type (Ityp)
3914 and then Present (Enum_Pos_To_Rep (Base_Type (Ityp)))
3919 Xnum := Expr_Value (First (Expressions (N)));
3923 Make_Attribute_Reference (Loc,
3924 Prefix => New_Occurrence_Of (Typ, Loc),
3925 Attribute_Name => Name_Max,
3926 Expressions => New_List
3927 (Make_Integer_Literal (Loc, 0),
3931 Make_Op_Subtract (Loc,
3933 Make_Attribute_Reference (Loc,
3934 Prefix => New_Occurrence_Of (Ityp, Loc),
3935 Attribute_Name => Name_Pos,
3937 Expressions => New_List (
3938 Make_Attribute_Reference (Loc,
3939 Prefix => Duplicate_Subexpr (Pref),
3940 Attribute_Name => Name_Last,
3941 Expressions => New_List (
3942 Make_Integer_Literal (Loc, Xnum))))),
3945 Make_Attribute_Reference (Loc,
3946 Prefix => New_Occurrence_Of (Ityp, Loc),
3947 Attribute_Name => Name_Pos,
3949 Expressions => New_List (
3950 Make_Attribute_Reference (Loc,
3952 Duplicate_Subexpr_No_Checks (Pref),
3953 Attribute_Name => Name_First,
3954 Expressions => New_List (
3955 Make_Integer_Literal (Loc, Xnum)))))),
3957 Right_Opnd => Make_Integer_Literal (Loc, 1)))));
3959 Analyze_And_Resolve (N, Typ, Suppress => All_Checks);
3962 -- If the prefix type is a constrained packed array type which
3963 -- already has a Packed_Array_Impl_Type representation defined,
3964 -- then replace this attribute with a reference to 'Range_Length
3965 -- of the appropriate index subtype (since otherwise the
3966 -- back end will try to give us the value of 'Length for
3967 -- this implementation type).s
3969 elsif Is_Constrained (Ptyp) then
3971 Make_Attribute_Reference (Loc,
3972 Attribute_Name => Name_Range_Length,
3973 Prefix => New_Occurrence_Of (Ityp, Loc)));
3974 Analyze_And_Resolve (N, Typ);
3979 elsif Is_Access_Type (Ptyp) then
3980 Apply_Access_Check (N);
3982 -- If the designated type is a packed array type, then we convert
3983 -- the reference to:
3986 -- xtyp'Pos (Pref'Last (Expr)) -
3987 -- xtyp'Pos (Pref'First (Expr)));
3989 -- This is a bit complex, but it is the easiest thing to do that
3990 -- works in all cases including enum types with holes xtyp here
3991 -- is the appropriate index type.
3994 Dtyp : constant Entity_Id := Designated_Type (Ptyp);
3998 if Is_Array_Type (Dtyp) and then Is_Packed (Dtyp) then
3999 Xtyp := Get_Index_Subtype (N);
4002 Make_Attribute_Reference (Loc,
4003 Prefix => New_Occurrence_Of (Typ, Loc),
4004 Attribute_Name => Name_Max,
4005 Expressions => New_List (
4006 Make_Integer_Literal (Loc, 0),
4009 Make_Integer_Literal (Loc, 1),
4010 Make_Op_Subtract (Loc,
4012 Make_Attribute_Reference (Loc,
4013 Prefix => New_Occurrence_Of (Xtyp, Loc),
4014 Attribute_Name => Name_Pos,
4015 Expressions => New_List (
4016 Make_Attribute_Reference (Loc,
4017 Prefix => Duplicate_Subexpr (Pref),
4018 Attribute_Name => Name_Last,
4020 New_Copy_List (Exprs)))),
4023 Make_Attribute_Reference (Loc,
4024 Prefix => New_Occurrence_Of (Xtyp, Loc),
4025 Attribute_Name => Name_Pos,
4026 Expressions => New_List (
4027 Make_Attribute_Reference (Loc,
4029 Duplicate_Subexpr_No_Checks (Pref),
4030 Attribute_Name => Name_First,
4032 New_Copy_List (Exprs)))))))));
4034 Analyze_And_Resolve (N, Typ);
4038 -- Otherwise leave it to the back end
4041 Apply_Universal_Integer_Attribute_Checks (N);
4045 -- Attribute Loop_Entry is replaced with a reference to a constant value
4046 -- which captures the prefix at the entry point of the related loop. The
4047 -- loop itself may be transformed into a conditional block.
4049 when Attribute_Loop_Entry =>
4050 Expand_Loop_Entry_Attribute (N);
4056 -- Transforms 'Machine into a call to the floating-point attribute
4057 -- function Machine in Fat_xxx (where xxx is the root type).
4058 -- Expansion is avoided for cases the back end can handle directly.
4060 when Attribute_Machine =>
4061 if not Is_Inline_Floating_Point_Attribute (N) then
4062 Expand_Fpt_Attribute_R (N);
4065 ----------------------
4066 -- Machine_Rounding --
4067 ----------------------
4069 -- Transforms 'Machine_Rounding into a call to the floating-point
4070 -- attribute function Machine_Rounding in Fat_xxx (where xxx is the root
4071 -- type). Expansion is avoided for cases the back end can handle
4074 when Attribute_Machine_Rounding =>
4075 if not Is_Inline_Floating_Point_Attribute (N) then
4076 Expand_Fpt_Attribute_R (N);
4083 -- Machine_Size is equivalent to Object_Size, so transform it into
4084 -- Object_Size and that way the back end never sees Machine_Size.
4086 when Attribute_Machine_Size =>
4088 Make_Attribute_Reference (Loc,
4089 Prefix => Prefix (N),
4090 Attribute_Name => Name_Object_Size));
4092 Analyze_And_Resolve (N, Typ);
4098 -- The only case that can get this far is the dynamic case of the old
4099 -- Ada 83 Mantissa attribute for the fixed-point case. For this case,
4106 -- ityp (System.Mantissa.Mantissa_Value
4107 -- (Integer'Integer_Value (typ'First),
4108 -- Integer'Integer_Value (typ'Last)));
4110 when Attribute_Mantissa => Mantissa : begin
4113 Make_Function_Call (Loc,
4114 Name => New_Occurrence_Of (RTE (RE_Mantissa_Value), Loc),
4116 Parameter_Associations => New_List (
4118 Make_Attribute_Reference (Loc,
4119 Prefix => New_Occurrence_Of (Standard_Integer, Loc),
4120 Attribute_Name => Name_Integer_Value,
4121 Expressions => New_List (
4123 Make_Attribute_Reference (Loc,
4124 Prefix => New_Occurrence_Of (Ptyp, Loc),
4125 Attribute_Name => Name_First))),
4127 Make_Attribute_Reference (Loc,
4128 Prefix => New_Occurrence_Of (Standard_Integer, Loc),
4129 Attribute_Name => Name_Integer_Value,
4130 Expressions => New_List (
4132 Make_Attribute_Reference (Loc,
4133 Prefix => New_Occurrence_Of (Ptyp, Loc),
4134 Attribute_Name => Name_Last)))))));
4136 Analyze_And_Resolve (N, Typ);
4143 when Attribute_Max =>
4144 Expand_Min_Max_Attribute (N);
4146 ----------------------------------
4147 -- Max_Size_In_Storage_Elements --
4148 ----------------------------------
4150 when Attribute_Max_Size_In_Storage_Elements => declare
4151 Typ : constant Entity_Id := Etype (N);
4154 Conversion_Added : Boolean := False;
4155 -- A flag which tracks whether the original attribute has been
4156 -- wrapped inside a type conversion.
4159 -- If the prefix is X'Class, we transform it into a direct reference
4160 -- to the class-wide type, because the back end must not see a 'Class
4161 -- reference. See also 'Size.
4163 if Is_Entity_Name (Pref)
4164 and then Is_Class_Wide_Type (Entity (Pref))
4166 Rewrite (Prefix (N), New_Occurrence_Of (Entity (Pref), Loc));
4170 Apply_Universal_Integer_Attribute_Checks (N);
4172 -- The universal integer check may sometimes add a type conversion,
4173 -- retrieve the original attribute reference from the expression.
4177 if Nkind (Attr) = N_Type_Conversion then
4178 Attr := Expression (Attr);
4179 Conversion_Added := True;
4182 pragma Assert (Nkind (Attr) = N_Attribute_Reference);
4184 -- Heap-allocated controlled objects contain two extra pointers which
4185 -- are not part of the actual type. Transform the attribute reference
4186 -- into a runtime expression to add the size of the hidden header.
4188 if Needs_Finalization (Ptyp)
4189 and then not Header_Size_Added (Attr)
4191 Set_Header_Size_Added (Attr);
4194 -- P'Max_Size_In_Storage_Elements +
4195 -- Universal_Integer
4196 -- (Header_Size_With_Padding (Ptyp'Alignment))
4200 Left_Opnd => Relocate_Node (Attr),
4202 Convert_To (Universal_Integer,
4203 Make_Function_Call (Loc,
4206 (RTE (RE_Header_Size_With_Padding), Loc),
4208 Parameter_Associations => New_List (
4209 Make_Attribute_Reference (Loc,
4211 New_Occurrence_Of (Ptyp, Loc),
4212 Attribute_Name => Name_Alignment))))));
4214 -- Add a conversion to the target type
4216 if not Conversion_Added then
4218 Make_Type_Conversion (Loc,
4219 Subtype_Mark => New_Occurrence_Of (Typ, Loc),
4220 Expression => Relocate_Node (Attr)));
4228 --------------------
4229 -- Mechanism_Code --
4230 --------------------
4232 when Attribute_Mechanism_Code =>
4234 -- We must replace the prefix i the renamed case
4236 if Is_Entity_Name (Pref)
4237 and then Present (Alias (Entity (Pref)))
4239 Set_Renamed_Subprogram (Pref, Alias (Entity (Pref)));
4246 when Attribute_Min =>
4247 Expand_Min_Max_Attribute (N);
4253 when Attribute_Mod => Mod_Case : declare
4254 Arg : constant Node_Id := Relocate_Node (First (Exprs));
4255 Hi : constant Node_Id := Type_High_Bound (Etype (Arg));
4256 Modv : constant Uint := Modulus (Btyp);
4260 -- This is not so simple. The issue is what type to use for the
4261 -- computation of the modular value.
4263 -- The easy case is when the modulus value is within the bounds
4264 -- of the signed integer type of the argument. In this case we can
4265 -- just do the computation in that signed integer type, and then
4266 -- do an ordinary conversion to the target type.
4268 if Modv <= Expr_Value (Hi) then
4273 Right_Opnd => Make_Integer_Literal (Loc, Modv))));
4275 -- Here we know that the modulus is larger than type'Last of the
4276 -- integer type. There are two cases to consider:
4278 -- a) The integer value is non-negative. In this case, it is
4279 -- returned as the result (since it is less than the modulus).
4281 -- b) The integer value is negative. In this case, we know that the
4282 -- result is modulus + value, where the value might be as small as
4283 -- -modulus. The trouble is what type do we use to do the subtract.
4284 -- No type will do, since modulus can be as big as 2**64, and no
4285 -- integer type accommodates this value. Let's do bit of algebra
4288 -- = modulus - (-value)
4289 -- = (modulus - 1) - (-value - 1)
4291 -- Now modulus - 1 is certainly in range of the modular type.
4292 -- -value is in the range 1 .. modulus, so -value -1 is in the
4293 -- range 0 .. modulus-1 which is in range of the modular type.
4294 -- Furthermore, (-value - 1) can be expressed as -(value + 1)
4295 -- which we can compute using the integer base type.
4297 -- Once this is done we analyze the if expression without range
4298 -- checks, because we know everything is in range, and we want
4299 -- to prevent spurious warnings on either branch.
4303 Make_If_Expression (Loc,
4304 Expressions => New_List (
4306 Left_Opnd => Duplicate_Subexpr (Arg),
4307 Right_Opnd => Make_Integer_Literal (Loc, 0)),
4310 Duplicate_Subexpr_No_Checks (Arg)),
4312 Make_Op_Subtract (Loc,
4314 Make_Integer_Literal (Loc,
4315 Intval => Modv - 1),
4321 Left_Opnd => Duplicate_Subexpr_No_Checks (Arg),
4323 Make_Integer_Literal (Loc,
4324 Intval => 1))))))));
4328 Analyze_And_Resolve (N, Btyp, Suppress => All_Checks);
4335 -- Transforms 'Model into a call to the floating-point attribute
4336 -- function Model in Fat_xxx (where xxx is the root type).
4337 -- Expansion is avoided for cases the back end can handle directly.
4339 when Attribute_Model =>
4340 if not Is_Inline_Floating_Point_Attribute (N) then
4341 Expand_Fpt_Attribute_R (N);
4348 -- The processing for Object_Size shares the processing for Size
4354 when Attribute_Old => Old : declare
4355 Typ : constant Entity_Id := Etype (N);
4356 CW_Temp : Entity_Id;
4362 -- Climb the parent chain looking for subprogram _Postconditions
4365 while Present (Subp) loop
4366 exit when Nkind (Subp) = N_Subprogram_Body
4367 and then Chars (Defining_Entity (Subp)) = Name_uPostconditions;
4369 -- If assertions are disabled, no need to create the declaration
4370 -- that preserves the value. The postcondition pragma in which
4371 -- 'Old appears will be checked or disabled according to the
4372 -- current policy in effect.
4374 if Nkind (Subp) = N_Pragma and then not Is_Checked (Subp) then
4378 Subp := Parent (Subp);
4381 -- 'Old can only appear in a postcondition, the generated body of
4382 -- _Postconditions must be in the tree.
4384 pragma Assert (Present (Subp));
4386 Temp := Make_Temporary (Loc, 'T', Pref);
4388 -- Set the entity kind now in order to mark the temporary as a
4389 -- handler of attribute 'Old's prefix.
4391 Set_Ekind (Temp, E_Constant);
4392 Set_Stores_Attribute_Old_Prefix (Temp);
4394 -- Push the scope of the related subprogram where _Postcondition
4395 -- resides as this ensures that the object will be analyzed in the
4398 Push_Scope (Scope (Defining_Entity (Subp)));
4400 -- Preserve the tag of the prefix by offering a specific view of the
4401 -- class-wide version of the prefix.
4403 if Is_Tagged_Type (Typ) then
4406 -- CW_Temp : constant Typ'Class := Typ'Class (Pref);
4408 CW_Temp := Make_Temporary (Loc, 'T');
4409 CW_Typ := Class_Wide_Type (Typ);
4411 Insert_Before_And_Analyze (Subp,
4412 Make_Object_Declaration (Loc,
4413 Defining_Identifier => CW_Temp,
4414 Constant_Present => True,
4415 Object_Definition => New_Occurrence_Of (CW_Typ, Loc),
4417 Convert_To (CW_Typ, Relocate_Node (Pref))));
4420 -- Temp : Typ renames Typ (CW_Temp);
4422 Insert_Before_And_Analyze (Subp,
4423 Make_Object_Renaming_Declaration (Loc,
4424 Defining_Identifier => Temp,
4425 Subtype_Mark => New_Occurrence_Of (Typ, Loc),
4427 Convert_To (Typ, New_Occurrence_Of (CW_Temp, Loc))));
4433 -- Temp : constant Typ := Pref;
4435 Insert_Before_And_Analyze (Subp,
4436 Make_Object_Declaration (Loc,
4437 Defining_Identifier => Temp,
4438 Constant_Present => True,
4439 Object_Definition => New_Occurrence_Of (Typ, Loc),
4440 Expression => Relocate_Node (Pref)));
4445 -- Ensure that the prefix of attribute 'Old is valid. The check must
4446 -- be inserted after the expansion of the attribute has taken place
4447 -- to reflect the new placement of the prefix.
4449 if Validity_Checks_On and then Validity_Check_Operands then
4450 Ensure_Valid (Pref);
4453 Rewrite (N, New_Occurrence_Of (Temp, Loc));
4456 ----------------------
4457 -- Overlaps_Storage --
4458 ----------------------
4460 when Attribute_Overlaps_Storage => Overlaps_Storage : declare
4461 Loc : constant Source_Ptr := Sloc (N);
4463 X : constant Node_Id := Prefix (N);
4464 Y : constant Node_Id := First (Expressions (N));
4467 X_Addr, Y_Addr : Node_Id;
4468 -- the expressions for their integer addresses
4470 X_Size, Y_Size : Node_Id;
4471 -- the expressions for their sizes
4476 -- Attribute expands into:
4478 -- if X'Address < Y'address then
4479 -- (X'address + X'Size - 1) >= Y'address
4481 -- (Y'address + Y'size - 1) >= X'Address
4484 -- with the proper address operations. We convert addresses to
4485 -- integer addresses to use predefined arithmetic. The size is
4486 -- expressed in storage units. We add copies of X_Addr and Y_Addr
4487 -- to prevent the appearance of the same node in two places in
4491 Unchecked_Convert_To (RTE (RE_Integer_Address),
4492 Make_Attribute_Reference (Loc,
4493 Attribute_Name => Name_Address,
4494 Prefix => New_Copy_Tree (X)));
4497 Unchecked_Convert_To (RTE (RE_Integer_Address),
4498 Make_Attribute_Reference (Loc,
4499 Attribute_Name => Name_Address,
4500 Prefix => New_Copy_Tree (Y)));
4503 Make_Op_Divide (Loc,
4505 Make_Attribute_Reference (Loc,
4506 Attribute_Name => Name_Size,
4507 Prefix => New_Copy_Tree (X)),
4509 Make_Integer_Literal (Loc, System_Storage_Unit));
4512 Make_Op_Divide (Loc,
4514 Make_Attribute_Reference (Loc,
4515 Attribute_Name => Name_Size,
4516 Prefix => New_Copy_Tree (Y)),
4518 Make_Integer_Literal (Loc, System_Storage_Unit));
4522 Left_Opnd => X_Addr,
4523 Right_Opnd => Y_Addr);
4526 Make_If_Expression (Loc, New_List (
4532 Left_Opnd => New_Copy_Tree (X_Addr),
4534 Make_Op_Subtract (Loc,
4535 Left_Opnd => X_Size,
4536 Right_Opnd => Make_Integer_Literal (Loc, 1))),
4537 Right_Opnd => Y_Addr),
4542 Left_Opnd => New_Copy_Tree (Y_Addr),
4544 Make_Op_Subtract (Loc,
4545 Left_Opnd => Y_Size,
4546 Right_Opnd => Make_Integer_Literal (Loc, 1))),
4547 Right_Opnd => X_Addr))));
4549 Analyze_And_Resolve (N, Standard_Boolean);
4550 end Overlaps_Storage;
4556 when Attribute_Output => Output : declare
4557 P_Type : constant Entity_Id := Entity (Pref);
4558 U_Type : constant Entity_Id := Underlying_Type (P_Type);
4566 -- If no underlying type, we have an error that will be diagnosed
4567 -- elsewhere, so here we just completely ignore the expansion.
4573 -- Stream operations can appear in user code even if the restriction
4574 -- No_Streams is active (for example, when instantiating a predefined
4575 -- container). In that case rewrite the attribute as a Raise to
4576 -- prevent any run-time use.
4578 if Restriction_Active (No_Streams) then
4580 Make_Raise_Program_Error (Sloc (N),
4581 Reason => PE_Stream_Operation_Not_Allowed));
4582 Set_Etype (N, Standard_Void_Type);
4586 -- If TSS for Output is present, just call it
4588 Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Output);
4590 if Present (Pname) then
4594 -- If there is a Stream_Convert pragma, use it, we rewrite
4596 -- sourcetyp'Output (stream, Item)
4600 -- strmtyp'Output (Stream, strmwrite (acttyp (Item)));
4602 -- where strmwrite is the given Write function that converts an
4603 -- argument of type sourcetyp or a type acctyp, from which it is
4604 -- derived to type strmtyp. The conversion to acttyp is required
4605 -- for the derived case.
4607 Prag := Get_Stream_Convert_Pragma (P_Type);
4609 if Present (Prag) then
4611 Next (Next (First (Pragma_Argument_Associations (Prag))));
4612 Wfunc := Entity (Expression (Arg3));
4615 Make_Attribute_Reference (Loc,
4616 Prefix => New_Occurrence_Of (Etype (Wfunc), Loc),
4617 Attribute_Name => Name_Output,
4618 Expressions => New_List (
4619 Relocate_Node (First (Exprs)),
4620 Make_Function_Call (Loc,
4621 Name => New_Occurrence_Of (Wfunc, Loc),
4622 Parameter_Associations => New_List (
4623 OK_Convert_To (Etype (First_Formal (Wfunc)),
4624 Relocate_Node (Next (First (Exprs)))))))));
4629 -- For elementary types, we call the W_xxx routine directly. Note
4630 -- that the effect of Write and Output is identical for the case
4631 -- of an elementary type (there are no discriminants or bounds).
4633 elsif Is_Elementary_Type (U_Type) then
4635 -- A special case arises if we have a defined _Write routine,
4636 -- since in this case we are required to call this routine.
4638 if Present (TSS (Base_Type (U_Type), TSS_Stream_Write)) then
4639 Build_Record_Or_Elementary_Output_Procedure
4640 (Loc, U_Type, Decl, Pname);
4641 Insert_Action (N, Decl);
4643 -- For normal cases, we call the W_xxx routine directly
4646 Rewrite (N, Build_Elementary_Write_Call (N));
4653 elsif Is_Array_Type (U_Type) then
4654 Build_Array_Output_Procedure (Loc, U_Type, Decl, Pname);
4655 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
4657 -- Class-wide case, first output external tag, then dispatch
4658 -- to the appropriate primitive Output function (RM 13.13.2(31)).
4660 elsif Is_Class_Wide_Type (P_Type) then
4662 -- No need to do anything else compiling under restriction
4663 -- No_Dispatching_Calls. During the semantic analysis we
4664 -- already notified such violation.
4666 if Restriction_Active (No_Dispatching_Calls) then
4671 Strm : constant Node_Id := First (Exprs);
4672 Item : constant Node_Id := Next (Strm);
4675 -- Ada 2005 (AI-344): Check that the accessibility level
4676 -- of the type of the output object is not deeper than
4677 -- that of the attribute's prefix type.
4679 -- if Get_Access_Level (Item'Tag)
4680 -- /= Get_Access_Level (P_Type'Tag)
4685 -- String'Output (Strm, External_Tag (Item'Tag));
4687 -- We cannot figure out a practical way to implement this
4688 -- accessibility check on virtual machines, so we omit it.
4690 if Ada_Version >= Ada_2005
4691 and then Tagged_Type_Expansion
4694 Make_Implicit_If_Statement (N,
4698 Build_Get_Access_Level (Loc,
4699 Make_Attribute_Reference (Loc,
4702 Duplicate_Subexpr (Item,
4704 Attribute_Name => Name_Tag)),
4707 Make_Integer_Literal (Loc,
4708 Type_Access_Level (P_Type))),
4711 New_List (Make_Raise_Statement (Loc,
4713 RTE (RE_Tag_Error), Loc)))));
4717 Make_Attribute_Reference (Loc,
4718 Prefix => New_Occurrence_Of (Standard_String, Loc),
4719 Attribute_Name => Name_Output,
4720 Expressions => New_List (
4721 Relocate_Node (Duplicate_Subexpr (Strm)),
4722 Make_Function_Call (Loc,
4724 New_Occurrence_Of (RTE (RE_External_Tag), Loc),
4725 Parameter_Associations => New_List (
4726 Make_Attribute_Reference (Loc,
4729 (Duplicate_Subexpr (Item, Name_Req => True)),
4730 Attribute_Name => Name_Tag))))));
4733 Pname := Find_Prim_Op (U_Type, TSS_Stream_Output);
4735 -- Tagged type case, use the primitive Output function
4737 elsif Is_Tagged_Type (U_Type) then
4738 Pname := Find_Prim_Op (U_Type, TSS_Stream_Output);
4740 -- All other record type cases, including protected records.
4741 -- The latter only arise for expander generated code for
4742 -- handling shared passive partition access.
4746 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
4748 -- Ada 2005 (AI-216): Program_Error is raised when executing
4749 -- the default implementation of the Output attribute of an
4750 -- unchecked union type if the type lacks default discriminant
4753 if Is_Unchecked_Union (Base_Type (U_Type))
4754 and then No (Discriminant_Constraint (U_Type))
4757 Make_Raise_Program_Error (Loc,
4758 Reason => PE_Unchecked_Union_Restriction));
4763 Build_Record_Or_Elementary_Output_Procedure
4764 (Loc, Base_Type (U_Type), Decl, Pname);
4765 Insert_Action (N, Decl);
4769 -- If we fall through, Pname is the name of the procedure to call
4771 Rewrite_Stream_Proc_Call (Pname);
4778 -- For enumeration types with a standard representation, Pos is
4779 -- handled by the back end.
4781 -- For enumeration types, with a non-standard representation we generate
4782 -- a call to the _Rep_To_Pos function created when the type was frozen.
4783 -- The call has the form
4785 -- _rep_to_pos (expr, flag)
4787 -- The parameter flag is True if range checks are enabled, causing
4788 -- Program_Error to be raised if the expression has an invalid
4789 -- representation, and False if range checks are suppressed.
4791 -- For integer types, Pos is equivalent to a simple integer
4792 -- conversion and we rewrite it as such
4794 when Attribute_Pos => Pos :
4796 Etyp : Entity_Id := Base_Type (Entity (Pref));
4799 -- Deal with zero/non-zero boolean values
4801 if Is_Boolean_Type (Etyp) then
4802 Adjust_Condition (First (Exprs));
4803 Etyp := Standard_Boolean;
4804 Set_Prefix (N, New_Occurrence_Of (Standard_Boolean, Loc));
4807 -- Case of enumeration type
4809 if Is_Enumeration_Type (Etyp) then
4811 -- Non-standard enumeration type (generate call)
4813 if Present (Enum_Pos_To_Rep (Etyp)) then
4814 Append_To (Exprs, Rep_To_Pos_Flag (Etyp, Loc));
4817 Make_Function_Call (Loc,
4819 New_Occurrence_Of (TSS (Etyp, TSS_Rep_To_Pos), Loc),
4820 Parameter_Associations => Exprs)));
4822 Analyze_And_Resolve (N, Typ);
4824 -- Standard enumeration type (do universal integer check)
4827 Apply_Universal_Integer_Attribute_Checks (N);
4830 -- Deal with integer types (replace by conversion)
4832 elsif Is_Integer_Type (Etyp) then
4833 Rewrite (N, Convert_To (Typ, First (Exprs)));
4834 Analyze_And_Resolve (N, Typ);
4843 -- We compute this if a component clause was present, otherwise we leave
4844 -- the computation up to the back end, since we don't know what layout
4847 when Attribute_Position => Position_Attr :
4849 CE : constant Entity_Id := Entity (Selector_Name (Pref));
4852 if Present (Component_Clause (CE)) then
4854 -- In Ada 2005 (or later) if we have the non-default bit order,
4855 -- then we return the original value as given in the component
4856 -- clause (RM 2005 13.5.2(2/2)).
4858 if Ada_Version >= Ada_2005
4859 and then Reverse_Bit_Order (Scope (CE))
4862 Make_Integer_Literal (Loc,
4863 Intval => Expr_Value (Position (Component_Clause (CE)))));
4865 -- Otherwise (Ada 83 or 95, or default bit order specified in
4866 -- later Ada version), return the normalized value.
4870 Make_Integer_Literal (Loc,
4871 Intval => Component_Bit_Offset (CE) / System_Storage_Unit));
4874 Analyze_And_Resolve (N, Typ);
4876 -- If back end is doing things, just apply universal integer checks
4879 Apply_Universal_Integer_Attribute_Checks (N);
4887 -- 1. Deal with enumeration types with holes.
4888 -- 2. For floating-point, generate call to attribute function.
4889 -- 3. For other cases, deal with constraint checking.
4891 when Attribute_Pred => Pred :
4893 Etyp : constant Entity_Id := Base_Type (Ptyp);
4897 -- For enumeration types with non-standard representations, we
4898 -- expand typ'Pred (x) into
4900 -- Pos_To_Rep (Rep_To_Pos (x) - 1)
4902 -- If the representation is contiguous, we compute instead
4903 -- Lit1 + Rep_to_Pos (x -1), to catch invalid representations.
4904 -- The conversion function Enum_Pos_To_Rep is defined on the
4905 -- base type, not the subtype, so we have to use the base type
4906 -- explicitly for this and other enumeration attributes.
4908 if Is_Enumeration_Type (Ptyp)
4909 and then Present (Enum_Pos_To_Rep (Etyp))
4911 if Has_Contiguous_Rep (Etyp) then
4913 Unchecked_Convert_To (Ptyp,
4916 Make_Integer_Literal (Loc,
4917 Enumeration_Rep (First_Literal (Ptyp))),
4919 Make_Function_Call (Loc,
4922 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
4924 Parameter_Associations =>
4926 Unchecked_Convert_To (Ptyp,
4927 Make_Op_Subtract (Loc,
4929 Unchecked_Convert_To (Standard_Integer,
4930 Relocate_Node (First (Exprs))),
4932 Make_Integer_Literal (Loc, 1))),
4933 Rep_To_Pos_Flag (Ptyp, Loc))))));
4936 -- Add Boolean parameter True, to request program errror if
4937 -- we have a bad representation on our hands. If checks are
4938 -- suppressed, then add False instead
4940 Append_To (Exprs, Rep_To_Pos_Flag (Ptyp, Loc));
4942 Make_Indexed_Component (Loc,
4945 (Enum_Pos_To_Rep (Etyp), Loc),
4946 Expressions => New_List (
4947 Make_Op_Subtract (Loc,
4949 Make_Function_Call (Loc,
4952 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
4953 Parameter_Associations => Exprs),
4954 Right_Opnd => Make_Integer_Literal (Loc, 1)))));
4957 Analyze_And_Resolve (N, Typ);
4959 -- For floating-point, we transform 'Pred into a call to the Pred
4960 -- floating-point attribute function in Fat_xxx (xxx is root type).
4961 -- Note that this function takes care of the overflow case.
4963 elsif Is_Floating_Point_Type (Ptyp) then
4964 Expand_Fpt_Attribute_R (N);
4965 Analyze_And_Resolve (N, Typ);
4967 -- For modular types, nothing to do (no overflow, since wraps)
4969 elsif Is_Modular_Integer_Type (Ptyp) then
4972 -- For other types, if argument is marked as needing a range check or
4973 -- overflow checking is enabled, we must generate a check.
4975 elsif not Overflow_Checks_Suppressed (Ptyp)
4976 or else Do_Range_Check (First (Exprs))
4978 Set_Do_Range_Check (First (Exprs), False);
4979 Expand_Pred_Succ_Attribute (N);
4987 -- Ada 2005 (AI-327): Dynamic ceiling priorities
4989 -- We rewrite X'Priority as the following run-time call:
4991 -- Get_Ceiling (X._Object)
4993 -- Note that although X'Priority is notionally an object, it is quite
4994 -- deliberately not defined as an aliased object in the RM. This means
4995 -- that it works fine to rewrite it as a call, without having to worry
4996 -- about complications that would other arise from X'Priority'Access,
4997 -- which is illegal, because of the lack of aliasing.
4999 when Attribute_Priority =>
5002 Conctyp : Entity_Id;
5003 Object_Parm : Node_Id;
5005 RT_Subprg_Name : Node_Id;
5008 -- Look for the enclosing concurrent type
5010 Conctyp := Current_Scope;
5011 while not Is_Concurrent_Type (Conctyp) loop
5012 Conctyp := Scope (Conctyp);
5015 pragma Assert (Is_Protected_Type (Conctyp));
5017 -- Generate the actual of the call
5019 Subprg := Current_Scope;
5020 while not Present (Protected_Body_Subprogram (Subprg)) loop
5021 Subprg := Scope (Subprg);
5024 -- Use of 'Priority inside protected entries and barriers (in
5025 -- both cases the type of the first formal of their expanded
5026 -- subprogram is Address)
5028 if Etype (First_Entity (Protected_Body_Subprogram (Subprg))) =
5032 New_Itype : Entity_Id;
5035 -- In the expansion of protected entries the type of the
5036 -- first formal of the Protected_Body_Subprogram is an
5037 -- Address. In order to reference the _object component
5040 -- type T is access p__ptTV;
5043 New_Itype := Create_Itype (E_Access_Type, N);
5044 Set_Etype (New_Itype, New_Itype);
5045 Set_Directly_Designated_Type (New_Itype,
5046 Corresponding_Record_Type (Conctyp));
5047 Freeze_Itype (New_Itype, N);
5050 -- T!(O)._object'unchecked_access
5053 Make_Attribute_Reference (Loc,
5055 Make_Selected_Component (Loc,
5057 Unchecked_Convert_To (New_Itype,
5060 (Protected_Body_Subprogram (Subprg)),
5063 Make_Identifier (Loc, Name_uObject)),
5064 Attribute_Name => Name_Unchecked_Access);
5067 -- Use of 'Priority inside a protected subprogram
5071 Make_Attribute_Reference (Loc,
5073 Make_Selected_Component (Loc,
5074 Prefix => New_Occurrence_Of
5076 (Protected_Body_Subprogram (Subprg)),
5078 Selector_Name => Make_Identifier (Loc, Name_uObject)),
5079 Attribute_Name => Name_Unchecked_Access);
5082 -- Select the appropriate run-time subprogram
5084 if Number_Entries (Conctyp) = 0 then
5086 New_Occurrence_Of (RTE (RE_Get_Ceiling), Loc);
5089 New_Occurrence_Of (RTE (RO_PE_Get_Ceiling), Loc);
5093 Make_Function_Call (Loc,
5094 Name => RT_Subprg_Name,
5095 Parameter_Associations => New_List (Object_Parm));
5099 -- Avoid the generation of extra checks on the pointer to the
5100 -- protected object.
5102 Analyze_And_Resolve (N, Typ, Suppress => Access_Check);
5109 when Attribute_Range_Length => Range_Length : begin
5111 -- The only special processing required is for the case where
5112 -- Range_Length is applied to an enumeration type with holes.
5113 -- In this case we transform
5119 -- X'Pos (X'Last) - X'Pos (X'First) + 1
5121 -- So that the result reflects the proper Pos values instead
5122 -- of the underlying representations.
5124 if Is_Enumeration_Type (Ptyp)
5125 and then Has_Non_Standard_Rep (Ptyp)
5130 Make_Op_Subtract (Loc,
5132 Make_Attribute_Reference (Loc,
5133 Attribute_Name => Name_Pos,
5134 Prefix => New_Occurrence_Of (Ptyp, Loc),
5135 Expressions => New_List (
5136 Make_Attribute_Reference (Loc,
5137 Attribute_Name => Name_Last,
5138 Prefix => New_Occurrence_Of (Ptyp, Loc)))),
5141 Make_Attribute_Reference (Loc,
5142 Attribute_Name => Name_Pos,
5143 Prefix => New_Occurrence_Of (Ptyp, Loc),
5144 Expressions => New_List (
5145 Make_Attribute_Reference (Loc,
5146 Attribute_Name => Name_First,
5147 Prefix => New_Occurrence_Of (Ptyp, Loc))))),
5149 Right_Opnd => Make_Integer_Literal (Loc, 1)));
5151 Analyze_And_Resolve (N, Typ);
5153 -- For all other cases, the attribute is handled by the back end, but
5154 -- we need to deal with the case of the range check on a universal
5158 Apply_Universal_Integer_Attribute_Checks (N);
5166 when Attribute_Read => Read : declare
5167 P_Type : constant Entity_Id := Entity (Pref);
5168 B_Type : constant Entity_Id := Base_Type (P_Type);
5169 U_Type : constant Entity_Id := Underlying_Type (P_Type);
5179 -- If no underlying type, we have an error that will be diagnosed
5180 -- elsewhere, so here we just completely ignore the expansion.
5186 -- Stream operations can appear in user code even if the restriction
5187 -- No_Streams is active (for example, when instantiating a predefined
5188 -- container). In that case rewrite the attribute as a Raise to
5189 -- prevent any run-time use.
5191 if Restriction_Active (No_Streams) then
5193 Make_Raise_Program_Error (Sloc (N),
5194 Reason => PE_Stream_Operation_Not_Allowed));
5195 Set_Etype (N, B_Type);
5199 -- The simple case, if there is a TSS for Read, just call it
5201 Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Read);
5203 if Present (Pname) then
5207 -- If there is a Stream_Convert pragma, use it, we rewrite
5209 -- sourcetyp'Read (stream, Item)
5213 -- Item := sourcetyp (strmread (strmtyp'Input (Stream)));
5215 -- where strmread is the given Read function that converts an
5216 -- argument of type strmtyp to type sourcetyp or a type from which
5217 -- it is derived. The conversion to sourcetyp is required in the
5220 -- A special case arises if Item is a type conversion in which
5221 -- case, we have to expand to:
5223 -- Itemx := typex (strmread (strmtyp'Input (Stream)));
5225 -- where Itemx is the expression of the type conversion (i.e.
5226 -- the actual object), and typex is the type of Itemx.
5228 Prag := Get_Stream_Convert_Pragma (P_Type);
5230 if Present (Prag) then
5231 Arg2 := Next (First (Pragma_Argument_Associations (Prag)));
5232 Rfunc := Entity (Expression (Arg2));
5233 Lhs := Relocate_Node (Next (First (Exprs)));
5235 OK_Convert_To (B_Type,
5236 Make_Function_Call (Loc,
5237 Name => New_Occurrence_Of (Rfunc, Loc),
5238 Parameter_Associations => New_List (
5239 Make_Attribute_Reference (Loc,
5242 (Etype (First_Formal (Rfunc)), Loc),
5243 Attribute_Name => Name_Input,
5244 Expressions => New_List (
5245 Relocate_Node (First (Exprs)))))));
5247 if Nkind (Lhs) = N_Type_Conversion then
5248 Lhs := Expression (Lhs);
5249 Rhs := Convert_To (Etype (Lhs), Rhs);
5253 Make_Assignment_Statement (Loc,
5255 Expression => Rhs));
5256 Set_Assignment_OK (Lhs);
5260 -- For elementary types, we call the I_xxx routine using the first
5261 -- parameter and then assign the result into the second parameter.
5262 -- We set Assignment_OK to deal with the conversion case.
5264 elsif Is_Elementary_Type (U_Type) then
5270 Lhs := Relocate_Node (Next (First (Exprs)));
5271 Rhs := Build_Elementary_Input_Call (N);
5273 if Nkind (Lhs) = N_Type_Conversion then
5274 Lhs := Expression (Lhs);
5275 Rhs := Convert_To (Etype (Lhs), Rhs);
5278 Set_Assignment_OK (Lhs);
5281 Make_Assignment_Statement (Loc,
5283 Expression => Rhs));
5291 elsif Is_Array_Type (U_Type) then
5292 Build_Array_Read_Procedure (N, U_Type, Decl, Pname);
5293 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
5295 -- Tagged type case, use the primitive Read function. Note that
5296 -- this will dispatch in the class-wide case which is what we want
5298 elsif Is_Tagged_Type (U_Type) then
5299 Pname := Find_Prim_Op (U_Type, TSS_Stream_Read);
5301 -- All other record type cases, including protected records. The
5302 -- latter only arise for expander generated code for handling
5303 -- shared passive partition access.
5307 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
5309 -- Ada 2005 (AI-216): Program_Error is raised when executing
5310 -- the default implementation of the Read attribute of an
5311 -- Unchecked_Union type.
5313 if Is_Unchecked_Union (Base_Type (U_Type)) then
5315 Make_Raise_Program_Error (Loc,
5316 Reason => PE_Unchecked_Union_Restriction));
5319 if Has_Discriminants (U_Type)
5321 (Discriminant_Default_Value (First_Discriminant (U_Type)))
5323 Build_Mutable_Record_Read_Procedure
5324 (Loc, Full_Base (U_Type), Decl, Pname);
5326 Build_Record_Read_Procedure
5327 (Loc, Full_Base (U_Type), Decl, Pname);
5330 -- Suppress checks, uninitialized or otherwise invalid
5331 -- data does not cause constraint errors to be raised for
5332 -- a complete record read.
5334 Insert_Action (N, Decl, All_Checks);
5338 Rewrite_Stream_Proc_Call (Pname);
5345 -- Ref is identical to To_Address, see To_Address for processing
5351 -- Transforms 'Remainder into a call to the floating-point attribute
5352 -- function Remainder in Fat_xxx (where xxx is the root type)
5354 when Attribute_Remainder =>
5355 Expand_Fpt_Attribute_RR (N);
5361 -- Transform 'Result into reference to _Result formal. At the point
5362 -- where a legal 'Result attribute is expanded, we know that we are in
5363 -- the context of a _Postcondition function with a _Result parameter.
5365 when Attribute_Result =>
5366 Rewrite (N, Make_Identifier (Loc, Chars => Name_uResult));
5367 Analyze_And_Resolve (N, Typ);
5373 -- The handling of the Round attribute is quite delicate. The processing
5374 -- in Sem_Attr introduced a conversion to universal real, reflecting the
5375 -- semantics of Round, but we do not want anything to do with universal
5376 -- real at runtime, since this corresponds to using floating-point
5379 -- What we have now is that the Etype of the Round attribute correctly
5380 -- indicates the final result type. The operand of the Round is the
5381 -- conversion to universal real, described above, and the operand of
5382 -- this conversion is the actual operand of Round, which may be the
5383 -- special case of a fixed point multiplication or division (Etype =
5386 -- The exapander will expand first the operand of the conversion, then
5387 -- the conversion, and finally the round attribute itself, since we
5388 -- always work inside out. But we cannot simply process naively in this
5389 -- order. In the semantic world where universal fixed and real really
5390 -- exist and have infinite precision, there is no problem, but in the
5391 -- implementation world, where universal real is a floating-point type,
5392 -- we would get the wrong result.
5394 -- So the approach is as follows. First, when expanding a multiply or
5395 -- divide whose type is universal fixed, we do nothing at all, instead
5396 -- deferring the operation till later.
5398 -- The actual processing is done in Expand_N_Type_Conversion which
5399 -- handles the special case of Round by looking at its parent to see if
5400 -- it is a Round attribute, and if it is, handling the conversion (or
5401 -- its fixed multiply/divide child) in an appropriate manner.
5403 -- This means that by the time we get to expanding the Round attribute
5404 -- itself, the Round is nothing more than a type conversion (and will
5405 -- often be a null type conversion), so we just replace it with the
5406 -- appropriate conversion operation.
5408 when Attribute_Round =>
5410 Convert_To (Etype (N), Relocate_Node (First (Exprs))));
5411 Analyze_And_Resolve (N);
5417 -- Transforms 'Rounding into a call to the floating-point attribute
5418 -- function Rounding in Fat_xxx (where xxx is the root type)
5419 -- Expansion is avoided for cases the back end can handle directly.
5421 when Attribute_Rounding =>
5422 if not Is_Inline_Floating_Point_Attribute (N) then
5423 Expand_Fpt_Attribute_R (N);
5430 -- Transforms 'Scaling into a call to the floating-point attribute
5431 -- function Scaling in Fat_xxx (where xxx is the root type)
5433 when Attribute_Scaling =>
5434 Expand_Fpt_Attribute_RI (N);
5436 -------------------------
5437 -- Simple_Storage_Pool --
5438 -------------------------
5440 when Attribute_Simple_Storage_Pool =>
5442 Make_Type_Conversion (Loc,
5443 Subtype_Mark => New_Occurrence_Of (Etype (N), Loc),
5444 Expression => New_Occurrence_Of (Entity (N), Loc)));
5445 Analyze_And_Resolve (N, Typ);
5451 when Attribute_Size |
5452 Attribute_Object_Size |
5453 Attribute_Value_Size |
5454 Attribute_VADS_Size => Size :
5461 -- Processing for VADS_Size case. Note that this processing removes
5462 -- all traces of VADS_Size from the tree, and completes all required
5463 -- processing for VADS_Size by translating the attribute reference
5464 -- to an appropriate Size or Object_Size reference.
5466 if Id = Attribute_VADS_Size
5467 or else (Use_VADS_Size and then Id = Attribute_Size)
5469 -- If the size is specified, then we simply use the specified
5470 -- size. This applies to both types and objects. The size of an
5471 -- object can be specified in the following ways:
5473 -- An explicit size object is given for an object
5474 -- A component size is specified for an indexed component
5475 -- A component clause is specified for a selected component
5476 -- The object is a component of a packed composite object
5478 -- If the size is specified, then VADS_Size of an object
5480 if (Is_Entity_Name (Pref)
5481 and then Present (Size_Clause (Entity (Pref))))
5483 (Nkind (Pref) = N_Component_Clause
5484 and then (Present (Component_Clause
5485 (Entity (Selector_Name (Pref))))
5486 or else Is_Packed (Etype (Prefix (Pref)))))
5488 (Nkind (Pref) = N_Indexed_Component
5489 and then (Component_Size (Etype (Prefix (Pref))) /= 0
5490 or else Is_Packed (Etype (Prefix (Pref)))))
5492 Set_Attribute_Name (N, Name_Size);
5494 -- Otherwise if we have an object rather than a type, then the
5495 -- VADS_Size attribute applies to the type of the object, rather
5496 -- than the object itself. This is one of the respects in which
5497 -- VADS_Size differs from Size.
5500 if (not Is_Entity_Name (Pref)
5501 or else not Is_Type (Entity (Pref)))
5502 and then (Is_Scalar_Type (Ptyp) or else Is_Constrained (Ptyp))
5504 Rewrite (Pref, New_Occurrence_Of (Ptyp, Loc));
5507 -- For a scalar type for which no size was explicitly given,
5508 -- VADS_Size means Object_Size. This is the other respect in
5509 -- which VADS_Size differs from Size.
5511 if Is_Scalar_Type (Ptyp) and then No (Size_Clause (Ptyp)) then
5512 Set_Attribute_Name (N, Name_Object_Size);
5514 -- In all other cases, Size and VADS_Size are the sane
5517 Set_Attribute_Name (N, Name_Size);
5522 -- If the prefix is X'Class, we transform it into a direct reference
5523 -- to the class-wide type, because the back end must not see a 'Class
5526 if Is_Entity_Name (Pref)
5527 and then Is_Class_Wide_Type (Entity (Pref))
5529 Rewrite (Prefix (N), New_Occurrence_Of (Entity (Pref), Loc));
5532 -- For X'Size applied to an object of a class-wide type, transform
5533 -- X'Size into a call to the primitive operation _Size applied to X.
5535 elsif Is_Class_Wide_Type (Ptyp) then
5537 -- No need to do anything else compiling under restriction
5538 -- No_Dispatching_Calls. During the semantic analysis we
5539 -- already noted this restriction violation.
5541 if Restriction_Active (No_Dispatching_Calls) then
5546 Make_Function_Call (Loc,
5547 Name => New_Occurrence_Of
5548 (Find_Prim_Op (Ptyp, Name_uSize), Loc),
5549 Parameter_Associations => New_List (Pref));
5551 if Typ /= Standard_Long_Long_Integer then
5553 -- The context is a specific integer type with which the
5554 -- original attribute was compatible. The function has a
5555 -- specific type as well, so to preserve the compatibility
5556 -- we must convert explicitly.
5558 New_Node := Convert_To (Typ, New_Node);
5561 Rewrite (N, New_Node);
5562 Analyze_And_Resolve (N, Typ);
5565 -- Case of known RM_Size of a type
5567 elsif (Id = Attribute_Size or else Id = Attribute_Value_Size)
5568 and then Is_Entity_Name (Pref)
5569 and then Is_Type (Entity (Pref))
5570 and then Known_Static_RM_Size (Entity (Pref))
5572 Siz := RM_Size (Entity (Pref));
5574 -- Case of known Esize of a type
5576 elsif Id = Attribute_Object_Size
5577 and then Is_Entity_Name (Pref)
5578 and then Is_Type (Entity (Pref))
5579 and then Known_Static_Esize (Entity (Pref))
5581 Siz := Esize (Entity (Pref));
5583 -- Case of known size of object
5585 elsif Id = Attribute_Size
5586 and then Is_Entity_Name (Pref)
5587 and then Is_Object (Entity (Pref))
5588 and then Known_Esize (Entity (Pref))
5589 and then Known_Static_Esize (Entity (Pref))
5591 Siz := Esize (Entity (Pref));
5593 -- For an array component, we can do Size in the front end
5594 -- if the component_size of the array is set.
5596 elsif Nkind (Pref) = N_Indexed_Component then
5597 Siz := Component_Size (Etype (Prefix (Pref)));
5599 -- For a record component, we can do Size in the front end if there
5600 -- is a component clause, or if the record is packed and the
5601 -- component's size is known at compile time.
5603 elsif Nkind (Pref) = N_Selected_Component then
5605 Rec : constant Entity_Id := Etype (Prefix (Pref));
5606 Comp : constant Entity_Id := Entity (Selector_Name (Pref));
5609 if Present (Component_Clause (Comp)) then
5610 Siz := Esize (Comp);
5612 elsif Is_Packed (Rec) then
5613 Siz := RM_Size (Ptyp);
5616 Apply_Universal_Integer_Attribute_Checks (N);
5621 -- All other cases are handled by the back end
5624 Apply_Universal_Integer_Attribute_Checks (N);
5626 -- If Size is applied to a formal parameter that is of a packed
5627 -- array subtype, then apply Size to the actual subtype.
5629 if Is_Entity_Name (Pref)
5630 and then Is_Formal (Entity (Pref))
5631 and then Is_Array_Type (Ptyp)
5632 and then Is_Packed (Ptyp)
5635 Make_Attribute_Reference (Loc,
5637 New_Occurrence_Of (Get_Actual_Subtype (Pref), Loc),
5638 Attribute_Name => Name_Size));
5639 Analyze_And_Resolve (N, Typ);
5642 -- If Size applies to a dereference of an access to unconstrained
5643 -- packed array, the back end needs to see its unconstrained
5644 -- nominal type, but also a hint to the actual constrained type.
5646 if Nkind (Pref) = N_Explicit_Dereference
5647 and then Is_Array_Type (Ptyp)
5648 and then not Is_Constrained (Ptyp)
5649 and then Is_Packed (Ptyp)
5651 Set_Actual_Designated_Subtype (Pref,
5652 Get_Actual_Subtype (Pref));
5658 -- Common processing for record and array component case
5660 if Siz /= No_Uint and then Siz /= 0 then
5662 CS : constant Boolean := Comes_From_Source (N);
5665 Rewrite (N, Make_Integer_Literal (Loc, Siz));
5667 -- This integer literal is not a static expression. We do not
5668 -- call Analyze_And_Resolve here, because this would activate
5669 -- the circuit for deciding that a static value was out of
5670 -- range, and we don't want that.
5672 -- So just manually set the type, mark the expression as non-
5673 -- static, and then ensure that the result is checked properly
5674 -- if the attribute comes from source (if it was internally
5675 -- generated, we never need a constraint check).
5678 Set_Is_Static_Expression (N, False);
5681 Apply_Constraint_Check (N, Typ);
5691 when Attribute_Storage_Pool =>
5693 Make_Type_Conversion (Loc,
5694 Subtype_Mark => New_Occurrence_Of (Etype (N), Loc),
5695 Expression => New_Occurrence_Of (Entity (N), Loc)));
5696 Analyze_And_Resolve (N, Typ);
5702 when Attribute_Storage_Size => Storage_Size : declare
5703 Alloc_Op : Entity_Id := Empty;
5707 -- Access type case, always go to the root type
5709 -- The case of access types results in a value of zero for the case
5710 -- where no storage size attribute clause has been given. If a
5711 -- storage size has been given, then the attribute is converted
5712 -- to a reference to the variable used to hold this value.
5714 if Is_Access_Type (Ptyp) then
5715 if Present (Storage_Size_Variable (Root_Type (Ptyp))) then
5717 Make_Attribute_Reference (Loc,
5718 Prefix => New_Occurrence_Of (Typ, Loc),
5719 Attribute_Name => Name_Max,
5720 Expressions => New_List (
5721 Make_Integer_Literal (Loc, 0),
5724 (Storage_Size_Variable (Root_Type (Ptyp)), Loc)))));
5726 elsif Present (Associated_Storage_Pool (Root_Type (Ptyp))) then
5728 -- If the access type is associated with a simple storage pool
5729 -- object, then attempt to locate the optional Storage_Size
5730 -- function of the simple storage pool type. If not found,
5731 -- then the result will default to zero.
5733 if Present (Get_Rep_Pragma (Root_Type (Ptyp),
5734 Name_Simple_Storage_Pool_Type))
5737 Pool_Type : constant Entity_Id :=
5738 Base_Type (Etype (Entity (N)));
5741 Alloc_Op := Get_Name_Entity_Id (Name_Storage_Size);
5742 while Present (Alloc_Op) loop
5743 if Scope (Alloc_Op) = Scope (Pool_Type)
5744 and then Present (First_Formal (Alloc_Op))
5745 and then Etype (First_Formal (Alloc_Op)) = Pool_Type
5750 Alloc_Op := Homonym (Alloc_Op);
5754 -- In the normal Storage_Pool case, retrieve the primitive
5755 -- function associated with the pool type.
5760 (Etype (Associated_Storage_Pool (Root_Type (Ptyp))),
5761 Attribute_Name (N));
5764 -- If Storage_Size wasn't found (can only occur in the simple
5765 -- storage pool case), then simply use zero for the result.
5767 if not Present (Alloc_Op) then
5768 Rewrite (N, Make_Integer_Literal (Loc, 0));
5770 -- Otherwise, rewrite the allocator as a call to pool type's
5771 -- Storage_Size function.
5776 Make_Function_Call (Loc,
5778 New_Occurrence_Of (Alloc_Op, Loc),
5780 Parameter_Associations => New_List (
5782 (Associated_Storage_Pool
5783 (Root_Type (Ptyp)), Loc)))));
5787 Rewrite (N, Make_Integer_Literal (Loc, 0));
5790 Analyze_And_Resolve (N, Typ);
5792 -- For tasks, we retrieve the size directly from the TCB. The
5793 -- size may depend on a discriminant of the type, and therefore
5794 -- can be a per-object expression, so type-level information is
5795 -- not sufficient in general. There are four cases to consider:
5797 -- a) If the attribute appears within a task body, the designated
5798 -- TCB is obtained by a call to Self.
5800 -- b) If the prefix of the attribute is the name of a task object,
5801 -- the designated TCB is the one stored in the corresponding record.
5803 -- c) If the prefix is a task type, the size is obtained from the
5804 -- size variable created for each task type
5806 -- d) If no Storage_Size was specified for the type, there is no
5807 -- size variable, and the value is a system-specific default.
5810 if In_Open_Scopes (Ptyp) then
5812 -- Storage_Size (Self)
5816 Make_Function_Call (Loc,
5818 New_Occurrence_Of (RTE (RE_Storage_Size), Loc),
5819 Parameter_Associations =>
5821 Make_Function_Call (Loc,
5823 New_Occurrence_Of (RTE (RE_Self), Loc))))));
5825 elsif not Is_Entity_Name (Pref)
5826 or else not Is_Type (Entity (Pref))
5828 -- Storage_Size (Rec (Obj).Size)
5832 Make_Function_Call (Loc,
5834 New_Occurrence_Of (RTE (RE_Storage_Size), Loc),
5835 Parameter_Associations =>
5837 Make_Selected_Component (Loc,
5839 Unchecked_Convert_To (
5840 Corresponding_Record_Type (Ptyp),
5841 New_Copy_Tree (Pref)),
5843 Make_Identifier (Loc, Name_uTask_Id))))));
5845 elsif Present (Storage_Size_Variable (Ptyp)) then
5847 -- Static Storage_Size pragma given for type: retrieve value
5848 -- from its allocated storage variable.
5852 Make_Function_Call (Loc,
5853 Name => New_Occurrence_Of (
5854 RTE (RE_Adjust_Storage_Size), Loc),
5855 Parameter_Associations =>
5858 Storage_Size_Variable (Ptyp), Loc)))));
5860 -- Get system default
5864 Make_Function_Call (Loc,
5867 RTE (RE_Default_Stack_Size), Loc))));
5870 Analyze_And_Resolve (N, Typ);
5878 when Attribute_Stream_Size =>
5880 Make_Integer_Literal (Loc, Intval => Get_Stream_Size (Ptyp)));
5881 Analyze_And_Resolve (N, Typ);
5887 -- 1. Deal with enumeration types with holes.
5888 -- 2. For floating-point, generate call to attribute function.
5889 -- 3. For other cases, deal with constraint checking.
5891 when Attribute_Succ => Succ : declare
5892 Etyp : constant Entity_Id := Base_Type (Ptyp);
5896 -- For enumeration types with non-standard representations, we
5897 -- expand typ'Succ (x) into
5899 -- Pos_To_Rep (Rep_To_Pos (x) + 1)
5901 -- If the representation is contiguous, we compute instead
5902 -- Lit1 + Rep_to_Pos (x+1), to catch invalid representations.
5904 if Is_Enumeration_Type (Ptyp)
5905 and then Present (Enum_Pos_To_Rep (Etyp))
5907 if Has_Contiguous_Rep (Etyp) then
5909 Unchecked_Convert_To (Ptyp,
5912 Make_Integer_Literal (Loc,
5913 Enumeration_Rep (First_Literal (Ptyp))),
5915 Make_Function_Call (Loc,
5918 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
5920 Parameter_Associations =>
5922 Unchecked_Convert_To (Ptyp,
5925 Unchecked_Convert_To (Standard_Integer,
5926 Relocate_Node (First (Exprs))),
5928 Make_Integer_Literal (Loc, 1))),
5929 Rep_To_Pos_Flag (Ptyp, Loc))))));
5931 -- Add Boolean parameter True, to request program errror if
5932 -- we have a bad representation on our hands. Add False if
5933 -- checks are suppressed.
5935 Append_To (Exprs, Rep_To_Pos_Flag (Ptyp, Loc));
5937 Make_Indexed_Component (Loc,
5940 (Enum_Pos_To_Rep (Etyp), Loc),
5941 Expressions => New_List (
5944 Make_Function_Call (Loc,
5947 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
5948 Parameter_Associations => Exprs),
5949 Right_Opnd => Make_Integer_Literal (Loc, 1)))));
5952 Analyze_And_Resolve (N, Typ);
5954 -- For floating-point, we transform 'Succ into a call to the Succ
5955 -- floating-point attribute function in Fat_xxx (xxx is root type)
5957 elsif Is_Floating_Point_Type (Ptyp) then
5958 Expand_Fpt_Attribute_R (N);
5959 Analyze_And_Resolve (N, Typ);
5961 -- For modular types, nothing to do (no overflow, since wraps)
5963 elsif Is_Modular_Integer_Type (Ptyp) then
5966 -- For other types, if argument is marked as needing a range check or
5967 -- overflow checking is enabled, we must generate a check.
5969 elsif not Overflow_Checks_Suppressed (Ptyp)
5970 or else Do_Range_Check (First (Exprs))
5972 Set_Do_Range_Check (First (Exprs), False);
5973 Expand_Pred_Succ_Attribute (N);
5981 -- Transforms X'Tag into a direct reference to the tag of X
5983 when Attribute_Tag => Tag : declare
5985 Prefix_Is_Type : Boolean;
5988 if Is_Entity_Name (Pref) and then Is_Type (Entity (Pref)) then
5989 Ttyp := Entity (Pref);
5990 Prefix_Is_Type := True;
5993 Prefix_Is_Type := False;
5996 if Is_Class_Wide_Type (Ttyp) then
5997 Ttyp := Root_Type (Ttyp);
6000 Ttyp := Underlying_Type (Ttyp);
6002 -- Ada 2005: The type may be a synchronized tagged type, in which
6003 -- case the tag information is stored in the corresponding record.
6005 if Is_Concurrent_Type (Ttyp) then
6006 Ttyp := Corresponding_Record_Type (Ttyp);
6009 if Prefix_Is_Type then
6011 -- For VMs we leave the type attribute unexpanded because
6012 -- there's not a dispatching table to reference.
6014 if Tagged_Type_Expansion then
6016 Unchecked_Convert_To (RTE (RE_Tag),
6018 (Node (First_Elmt (Access_Disp_Table (Ttyp))), Loc)));
6019 Analyze_And_Resolve (N, RTE (RE_Tag));
6022 -- Ada 2005 (AI-251): The use of 'Tag in the sources always
6023 -- references the primary tag of the actual object. If 'Tag is
6024 -- applied to class-wide interface objects we generate code that
6025 -- displaces "this" to reference the base of the object.
6027 elsif Comes_From_Source (N)
6028 and then Is_Class_Wide_Type (Etype (Prefix (N)))
6029 and then Is_Interface (Etype (Prefix (N)))
6032 -- (To_Tag_Ptr (Prefix'Address)).all
6034 -- Note that Prefix'Address is recursively expanded into a call
6035 -- to Base_Address (Obj.Tag)
6037 -- Not needed for VM targets, since all handled by the VM
6039 if Tagged_Type_Expansion then
6041 Make_Explicit_Dereference (Loc,
6042 Unchecked_Convert_To (RTE (RE_Tag_Ptr),
6043 Make_Attribute_Reference (Loc,
6044 Prefix => Relocate_Node (Pref),
6045 Attribute_Name => Name_Address))));
6046 Analyze_And_Resolve (N, RTE (RE_Tag));
6051 Make_Selected_Component (Loc,
6052 Prefix => Relocate_Node (Pref),
6054 New_Occurrence_Of (First_Tag_Component (Ttyp), Loc)));
6055 Analyze_And_Resolve (N, RTE (RE_Tag));
6063 -- Transforms 'Terminated attribute into a call to Terminated function
6065 when Attribute_Terminated => Terminated :
6067 -- The prefix of Terminated is of a task interface class-wide type.
6069 -- terminated (Task_Id (Pref._disp_get_task_id));
6071 if Ada_Version >= Ada_2005
6072 and then Ekind (Ptyp) = E_Class_Wide_Type
6073 and then Is_Interface (Ptyp)
6074 and then Is_Task_Interface (Ptyp)
6077 Make_Function_Call (Loc,
6079 New_Occurrence_Of (RTE (RE_Terminated), Loc),
6080 Parameter_Associations => New_List (
6081 Make_Unchecked_Type_Conversion (Loc,
6083 New_Occurrence_Of (RTE (RO_ST_Task_Id), Loc),
6085 Make_Selected_Component (Loc,
6087 New_Copy_Tree (Pref),
6089 Make_Identifier (Loc, Name_uDisp_Get_Task_Id))))));
6091 elsif Restricted_Profile then
6093 Build_Call_With_Task (Pref, RTE (RE_Restricted_Terminated)));
6097 Build_Call_With_Task (Pref, RTE (RE_Terminated)));
6100 Analyze_And_Resolve (N, Standard_Boolean);
6107 -- Transforms System'To_Address (X) and System.Address'Ref (X) into
6108 -- unchecked conversion from (integral) type of X to type address.
6110 when Attribute_To_Address | Attribute_Ref =>
6112 Unchecked_Convert_To (RTE (RE_Address),
6113 Relocate_Node (First (Exprs))));
6114 Analyze_And_Resolve (N, RTE (RE_Address));
6120 when Attribute_To_Any => To_Any : declare
6121 P_Type : constant Entity_Id := Etype (Pref);
6122 Decls : constant List_Id := New_List;
6128 Relocate_Node (First (Exprs))), Decls));
6129 Insert_Actions (N, Decls);
6130 Analyze_And_Resolve (N, RTE (RE_Any));
6137 -- Transforms 'Truncation into a call to the floating-point attribute
6138 -- function Truncation in Fat_xxx (where xxx is the root type).
6139 -- Expansion is avoided for cases the back end can handle directly.
6141 when Attribute_Truncation =>
6142 if not Is_Inline_Floating_Point_Attribute (N) then
6143 Expand_Fpt_Attribute_R (N);
6150 when Attribute_TypeCode => TypeCode : declare
6151 P_Type : constant Entity_Id := Etype (Pref);
6152 Decls : constant List_Id := New_List;
6154 Rewrite (N, Build_TypeCode_Call (Loc, P_Type, Decls));
6155 Insert_Actions (N, Decls);
6156 Analyze_And_Resolve (N, RTE (RE_TypeCode));
6159 -----------------------
6160 -- Unbiased_Rounding --
6161 -----------------------
6163 -- Transforms 'Unbiased_Rounding into a call to the floating-point
6164 -- attribute function Unbiased_Rounding in Fat_xxx (where xxx is the
6165 -- root type). Expansion is avoided for cases the back end can handle
6168 when Attribute_Unbiased_Rounding =>
6169 if not Is_Inline_Floating_Point_Attribute (N) then
6170 Expand_Fpt_Attribute_R (N);
6177 when Attribute_Update =>
6178 Expand_Update_Attribute (N);
6184 -- The processing for VADS_Size is shared with Size
6190 -- For enumeration types with a standard representation, and for all
6191 -- other types, Val is handled by the back end. For enumeration types
6192 -- with a non-standard representation we use the _Pos_To_Rep array that
6193 -- was created when the type was frozen.
6195 when Attribute_Val => Val : declare
6196 Etyp : constant Entity_Id := Base_Type (Entity (Pref));
6199 if Is_Enumeration_Type (Etyp)
6200 and then Present (Enum_Pos_To_Rep (Etyp))
6202 if Has_Contiguous_Rep (Etyp) then
6204 Rep_Node : constant Node_Id :=
6205 Unchecked_Convert_To (Etyp,
6208 Make_Integer_Literal (Loc,
6209 Enumeration_Rep (First_Literal (Etyp))),
6211 (Convert_To (Standard_Integer,
6212 Relocate_Node (First (Exprs))))));
6216 Unchecked_Convert_To (Etyp,
6219 Make_Integer_Literal (Loc,
6220 Enumeration_Rep (First_Literal (Etyp))),
6222 Make_Function_Call (Loc,
6225 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
6226 Parameter_Associations => New_List (
6228 Rep_To_Pos_Flag (Etyp, Loc))))));
6233 Make_Indexed_Component (Loc,
6234 Prefix => New_Occurrence_Of (Enum_Pos_To_Rep (Etyp), Loc),
6235 Expressions => New_List (
6236 Convert_To (Standard_Integer,
6237 Relocate_Node (First (Exprs))))));
6240 Analyze_And_Resolve (N, Typ);
6242 -- If the argument is marked as requiring a range check then generate
6245 elsif Do_Range_Check (First (Exprs)) then
6246 Generate_Range_Check (First (Exprs), Etyp, CE_Range_Check_Failed);
6254 -- The code for valid is dependent on the particular types involved.
6255 -- See separate sections below for the generated code in each case.
6257 when Attribute_Valid => Valid : declare
6258 Btyp : Entity_Id := Base_Type (Ptyp);
6261 Save_Validity_Checks_On : constant Boolean := Validity_Checks_On;
6262 -- Save the validity checking mode. We always turn off validity
6263 -- checking during process of 'Valid since this is one place
6264 -- where we do not want the implicit validity checks to intefere
6265 -- with the explicit validity check that the programmer is doing.
6267 function Make_Range_Test return Node_Id;
6268 -- Build the code for a range test of the form
6269 -- Btyp!(Pref) in Btyp!(Ptyp'First) .. Btyp!(Ptyp'Last)
6271 ---------------------
6272 -- Make_Range_Test --
6273 ---------------------
6275 function Make_Range_Test return Node_Id is
6276 Temp : constant Node_Id := Duplicate_Subexpr (Pref);
6279 -- The value whose validity is being checked has been captured in
6280 -- an object declaration. We certainly don't want this object to
6281 -- appear valid because the declaration initializes it.
6283 if Is_Entity_Name (Temp) then
6284 Set_Is_Known_Valid (Entity (Temp), False);
6290 Unchecked_Convert_To (Btyp, Temp),
6294 Unchecked_Convert_To (Btyp,
6295 Make_Attribute_Reference (Loc,
6296 Prefix => New_Occurrence_Of (Ptyp, Loc),
6297 Attribute_Name => Name_First)),
6299 Unchecked_Convert_To (Btyp,
6300 Make_Attribute_Reference (Loc,
6301 Prefix => New_Occurrence_Of (Ptyp, Loc),
6302 Attribute_Name => Name_Last))));
6303 end Make_Range_Test;
6305 -- Start of processing for Attribute_Valid
6308 -- Do not expand sourced code 'Valid reference in CodePeer mode,
6309 -- will be handled by the back-end directly.
6311 if CodePeer_Mode and then Comes_From_Source (N) then
6315 -- Turn off validity checks. We do not want any implicit validity
6316 -- checks to intefere with the explicit check from the attribute
6318 Validity_Checks_On := False;
6320 -- Retrieve the base type. Handle the case where the base type is a
6321 -- private enumeration type.
6323 if Is_Private_Type (Btyp) and then Present (Full_View (Btyp)) then
6324 Btyp := Full_View (Btyp);
6327 -- Floating-point case. This case is handled by the Valid attribute
6328 -- code in the floating-point attribute run-time library.
6330 if Is_Floating_Point_Type (Ptyp) then
6331 Float_Valid : declare
6335 function Get_Fat_Entity (Nam : Name_Id) return Entity_Id;
6336 -- Return entity for Pkg.Nam
6338 --------------------
6339 -- Get_Fat_Entity --
6340 --------------------
6342 function Get_Fat_Entity (Nam : Name_Id) return Entity_Id is
6343 Exp_Name : constant Node_Id :=
6344 Make_Selected_Component (Loc,
6345 Prefix => New_Occurrence_Of (RTE (Pkg), Loc),
6346 Selector_Name => Make_Identifier (Loc, Nam));
6348 Find_Selected_Component (Exp_Name);
6349 return Entity (Exp_Name);
6352 -- Start of processing for Float_Valid
6355 -- The C and AAMP back-ends handle Valid for fpt types
6357 if Generate_C_Code or else Float_Rep (Btyp) = AAMP then
6358 Analyze_And_Resolve (Pref, Ptyp);
6359 Set_Etype (N, Standard_Boolean);
6363 Find_Fat_Info (Ptyp, Ftp, Pkg);
6365 -- If the prefix is a reverse SSO component, or is possibly
6366 -- unaligned, first create a temporary copy that is in
6367 -- native SSO, and properly aligned. Make it Volatile to
6368 -- prevent folding in the back-end. Note that we use an
6369 -- intermediate constrained string type to initialize the
6370 -- temporary, as the value at hand might be invalid, and in
6371 -- that case it cannot be copied using a floating point
6374 if In_Reverse_Storage_Order_Object (Pref)
6375 or else Is_Possibly_Unaligned_Object (Pref)
6378 Temp : constant Entity_Id :=
6379 Make_Temporary (Loc, 'F');
6381 Fat_S : constant Entity_Id :=
6382 Get_Fat_Entity (Name_S);
6383 -- Constrained string subtype of appropriate size
6385 Fat_P : constant Entity_Id :=
6386 Get_Fat_Entity (Name_P);
6389 Decl : constant Node_Id :=
6390 Make_Object_Declaration (Loc,
6391 Defining_Identifier => Temp,
6392 Aliased_Present => True,
6393 Object_Definition =>
6394 New_Occurrence_Of (Ptyp, Loc));
6397 Set_Aspect_Specifications (Decl, New_List (
6398 Make_Aspect_Specification (Loc,
6400 Make_Identifier (Loc, Name_Volatile))));
6406 Make_Assignment_Statement (Loc,
6408 Make_Explicit_Dereference (Loc,
6410 Unchecked_Convert_To (Fat_P,
6411 Make_Attribute_Reference (Loc,
6413 New_Occurrence_Of (Temp, Loc),
6415 Name_Unrestricted_Access))),
6417 Unchecked_Convert_To (Fat_S,
6418 Relocate_Node (Pref)))),
6420 Suppress => All_Checks);
6422 Rewrite (Pref, New_Occurrence_Of (Temp, Loc));
6426 -- We now have an object of the proper endianness and
6427 -- alignment, and can construct a Valid attribute.
6429 -- We make sure the prefix of this valid attribute is
6430 -- marked as not coming from source, to avoid losing
6431 -- warnings from 'Valid looking like a possible update.
6433 Set_Comes_From_Source (Pref, False);
6435 Expand_Fpt_Attribute
6436 (N, Pkg, Name_Valid,
6438 Make_Attribute_Reference (Loc,
6439 Prefix => Unchecked_Convert_To (Ftp, Pref),
6440 Attribute_Name => Name_Unrestricted_Access)));
6443 -- One more task, we still need a range check. Required
6444 -- only if we have a constraint, since the Valid routine
6445 -- catches infinities properly (infinities are never valid).
6447 -- The way we do the range check is simply to create the
6448 -- expression: Valid (N) and then Base_Type(Pref) in Typ.
6450 if not Subtypes_Statically_Match (Ptyp, Btyp) then
6453 Left_Opnd => Relocate_Node (N),
6456 Left_Opnd => Convert_To (Btyp, Pref),
6457 Right_Opnd => New_Occurrence_Of (Ptyp, Loc))));
6461 -- Enumeration type with holes
6463 -- For enumeration types with holes, the Pos value constructed by
6464 -- the Enum_Rep_To_Pos function built in Exp_Ch3 called with a
6465 -- second argument of False returns minus one for an invalid value,
6466 -- and the non-negative pos value for a valid value, so the
6467 -- expansion of X'Valid is simply:
6469 -- type(X)'Pos (X) >= 0
6471 -- We can't quite generate it that way because of the requirement
6472 -- for the non-standard second argument of False in the resulting
6473 -- rep_to_pos call, so we have to explicitly create:
6475 -- _rep_to_pos (X, False) >= 0
6477 -- If we have an enumeration subtype, we also check that the
6478 -- value is in range:
6480 -- _rep_to_pos (X, False) >= 0
6482 -- (X >= type(X)'First and then type(X)'Last <= X)
6484 elsif Is_Enumeration_Type (Ptyp)
6485 and then Present (Enum_Pos_To_Rep (Btyp))
6490 Make_Function_Call (Loc,
6492 New_Occurrence_Of (TSS (Btyp, TSS_Rep_To_Pos), Loc),
6493 Parameter_Associations => New_List (
6495 New_Occurrence_Of (Standard_False, Loc))),
6496 Right_Opnd => Make_Integer_Literal (Loc, 0));
6500 (Type_Low_Bound (Ptyp) /= Type_Low_Bound (Btyp)
6502 Type_High_Bound (Ptyp) /= Type_High_Bound (Btyp))
6504 -- The call to Make_Range_Test will create declarations
6505 -- that need a proper insertion point, but Pref is now
6506 -- attached to a node with no ancestor. Attach to tree
6507 -- even if it is to be rewritten below.
6509 Set_Parent (Tst, Parent (N));
6513 Left_Opnd => Make_Range_Test,
6519 -- Fortran convention booleans
6521 -- For the very special case of Fortran convention booleans, the
6522 -- value is always valid, since it is an integer with the semantics
6523 -- that non-zero is true, and any value is permissible.
6525 elsif Is_Boolean_Type (Ptyp)
6526 and then Convention (Ptyp) = Convention_Fortran
6528 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
6530 -- For biased representations, we will be doing an unchecked
6531 -- conversion without unbiasing the result. That means that the range
6532 -- test has to take this into account, and the proper form of the
6535 -- Btyp!(Pref) < Btyp!(Ptyp'Range_Length)
6537 elsif Has_Biased_Representation (Ptyp) then
6538 Btyp := RTE (RE_Unsigned_32);
6542 Unchecked_Convert_To (Btyp, Duplicate_Subexpr (Pref)),
6544 Unchecked_Convert_To (Btyp,
6545 Make_Attribute_Reference (Loc,
6546 Prefix => New_Occurrence_Of (Ptyp, Loc),
6547 Attribute_Name => Name_Range_Length))));
6549 -- For all other scalar types, what we want logically is a
6552 -- X in type(X)'First .. type(X)'Last
6554 -- But that's precisely what won't work because of possible
6555 -- unwanted optimization (and indeed the basic motivation for
6556 -- the Valid attribute is exactly that this test does not work).
6557 -- What will work is:
6559 -- Btyp!(X) >= Btyp!(type(X)'First)
6561 -- Btyp!(X) <= Btyp!(type(X)'Last)
6563 -- where Btyp is an integer type large enough to cover the full
6564 -- range of possible stored values (i.e. it is chosen on the basis
6565 -- of the size of the type, not the range of the values). We write
6566 -- this as two tests, rather than a range check, so that static
6567 -- evaluation will easily remove either or both of the checks if
6568 -- they can be -statically determined to be true (this happens
6569 -- when the type of X is static and the range extends to the full
6570 -- range of stored values).
6572 -- Unsigned types. Note: it is safe to consider only whether the
6573 -- subtype is unsigned, since we will in that case be doing all
6574 -- unsigned comparisons based on the subtype range. Since we use the
6575 -- actual subtype object size, this is appropriate.
6577 -- For example, if we have
6579 -- subtype x is integer range 1 .. 200;
6580 -- for x'Object_Size use 8;
6582 -- Now the base type is signed, but objects of this type are bits
6583 -- unsigned, and doing an unsigned test of the range 1 to 200 is
6584 -- correct, even though a value greater than 127 looks signed to a
6585 -- signed comparison.
6587 elsif Is_Unsigned_Type (Ptyp) then
6588 if Esize (Ptyp) <= 32 then
6589 Btyp := RTE (RE_Unsigned_32);
6591 Btyp := RTE (RE_Unsigned_64);
6594 Rewrite (N, Make_Range_Test);
6599 if Esize (Ptyp) <= Esize (Standard_Integer) then
6600 Btyp := Standard_Integer;
6602 Btyp := Universal_Integer;
6605 Rewrite (N, Make_Range_Test);
6608 -- If a predicate is present, then we do the predicate test, even if
6609 -- within the predicate function (infinite recursion is warned about
6610 -- in Sem_Attr in that case).
6613 Pred_Func : constant Entity_Id := Predicate_Function (Ptyp);
6616 if Present (Pred_Func) then
6619 Left_Opnd => Relocate_Node (N),
6620 Right_Opnd => Make_Predicate_Call (Ptyp, Pref)));
6624 Analyze_And_Resolve (N, Standard_Boolean);
6625 Validity_Checks_On := Save_Validity_Checks_On;
6632 when Attribute_Valid_Scalars => Valid_Scalars : declare
6636 if Present (Underlying_Type (Ptyp)) then
6637 Ftyp := Underlying_Type (Ptyp);
6642 -- Replace by True if no scalar parts
6644 if not Scalar_Part_Present (Ftyp) then
6645 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
6647 -- For scalar types, Valid_Scalars is the same as Valid
6649 elsif Is_Scalar_Type (Ftyp) then
6651 Make_Attribute_Reference (Loc,
6652 Attribute_Name => Name_Valid,
6655 -- For array types, we construct a function that determines if there
6656 -- are any non-valid scalar subcomponents, and call the function.
6657 -- We only do this for arrays whose component type needs checking
6659 elsif Is_Array_Type (Ftyp)
6660 and then Scalar_Part_Present (Component_Type (Ftyp))
6663 Make_Function_Call (Loc,
6665 New_Occurrence_Of (Build_Array_VS_Func (Ftyp, N), Loc),
6666 Parameter_Associations => New_List (Pref)));
6668 -- For record types, we construct a function that determines if there
6669 -- are any non-valid scalar subcomponents, and call the function.
6671 elsif Is_Record_Type (Ftyp)
6672 and then Nkind (Type_Definition (Declaration_Node (Ftyp))) =
6676 Make_Function_Call (Loc,
6678 New_Occurrence_Of (Build_Record_VS_Func (Ftyp, N), Loc),
6679 Parameter_Associations => New_List (Pref)));
6681 -- Other record types or types with discriminants
6683 elsif Is_Record_Type (Ftyp) or else Has_Discriminants (Ptyp) then
6685 -- Build expression with list of equality tests
6693 X := New_Occurrence_Of (Standard_True, Loc);
6694 C := First_Component_Or_Discriminant (Ptyp);
6695 while Present (C) loop
6696 if not Scalar_Part_Present (Etype (C)) then
6698 elsif Is_Scalar_Type (Etype (C)) then
6701 A := Name_Valid_Scalars;
6708 Make_Attribute_Reference (Loc,
6709 Attribute_Name => A,
6711 Make_Selected_Component (Loc,
6713 Duplicate_Subexpr (Pref, Name_Req => True),
6715 New_Occurrence_Of (C, Loc))));
6717 Next_Component_Or_Discriminant (C);
6723 -- For all other types, result is True
6726 Rewrite (N, New_Occurrence_Of (Standard_Boolean, Loc));
6729 -- Result is always boolean, but never static
6731 Analyze_And_Resolve (N, Standard_Boolean);
6732 Set_Is_Static_Expression (N, False);
6739 -- Value attribute is handled in separate unit Exp_Imgv
6741 when Attribute_Value =>
6742 Exp_Imgv.Expand_Value_Attribute (N);
6748 -- The processing for Value_Size shares the processing for Size
6754 -- The processing for Version shares the processing for Body_Version
6760 -- Wide_Image attribute is handled in separate unit Exp_Imgv
6762 when Attribute_Wide_Image =>
6763 Exp_Imgv.Expand_Wide_Image_Attribute (N);
6765 ---------------------
6766 -- Wide_Wide_Image --
6767 ---------------------
6769 -- Wide_Wide_Image attribute is handled in separate unit Exp_Imgv
6771 when Attribute_Wide_Wide_Image =>
6772 Exp_Imgv.Expand_Wide_Wide_Image_Attribute (N);
6778 -- We expand typ'Wide_Value (X) into
6781 -- (Wide_String_To_String (X, Wide_Character_Encoding_Method))
6783 -- Wide_String_To_String is a runtime function that converts its wide
6784 -- string argument to String, converting any non-translatable characters
6785 -- into appropriate escape sequences. This preserves the required
6786 -- semantics of Wide_Value in all cases, and results in a very simple
6787 -- implementation approach.
6789 -- Note: for this approach to be fully standard compliant for the cases
6790 -- where typ is Wide_Character and Wide_Wide_Character, the encoding
6791 -- method must cover the entire character range (e.g. UTF-8). But that
6792 -- is a reasonable requirement when dealing with encoded character
6793 -- sequences. Presumably if one of the restrictive encoding mechanisms
6794 -- is in use such as Shift-JIS, then characters that cannot be
6795 -- represented using this encoding will not appear in any case.
6797 when Attribute_Wide_Value => Wide_Value :
6800 Make_Attribute_Reference (Loc,
6802 Attribute_Name => Name_Value,
6804 Expressions => New_List (
6805 Make_Function_Call (Loc,
6807 New_Occurrence_Of (RTE (RE_Wide_String_To_String), Loc),
6809 Parameter_Associations => New_List (
6810 Relocate_Node (First (Exprs)),
6811 Make_Integer_Literal (Loc,
6812 Intval => Int (Wide_Character_Encoding_Method)))))));
6814 Analyze_And_Resolve (N, Typ);
6817 ---------------------
6818 -- Wide_Wide_Value --
6819 ---------------------
6821 -- We expand typ'Wide_Value_Value (X) into
6824 -- (Wide_Wide_String_To_String (X, Wide_Character_Encoding_Method))
6826 -- Wide_Wide_String_To_String is a runtime function that converts its
6827 -- wide string argument to String, converting any non-translatable
6828 -- characters into appropriate escape sequences. This preserves the
6829 -- required semantics of Wide_Wide_Value in all cases, and results in a
6830 -- very simple implementation approach.
6832 -- It's not quite right where typ = Wide_Wide_Character, because the
6833 -- encoding method may not cover the whole character type ???
6835 when Attribute_Wide_Wide_Value => Wide_Wide_Value :
6838 Make_Attribute_Reference (Loc,
6840 Attribute_Name => Name_Value,
6842 Expressions => New_List (
6843 Make_Function_Call (Loc,
6846 (RTE (RE_Wide_Wide_String_To_String), Loc),
6848 Parameter_Associations => New_List (
6849 Relocate_Node (First (Exprs)),
6850 Make_Integer_Literal (Loc,
6851 Intval => Int (Wide_Character_Encoding_Method)))))));
6853 Analyze_And_Resolve (N, Typ);
6854 end Wide_Wide_Value;
6856 ---------------------
6857 -- Wide_Wide_Width --
6858 ---------------------
6860 -- Wide_Wide_Width attribute is handled in separate unit Exp_Imgv
6862 when Attribute_Wide_Wide_Width =>
6863 Exp_Imgv.Expand_Width_Attribute (N, Wide_Wide);
6869 -- Wide_Width attribute is handled in separate unit Exp_Imgv
6871 when Attribute_Wide_Width =>
6872 Exp_Imgv.Expand_Width_Attribute (N, Wide);
6878 -- Width attribute is handled in separate unit Exp_Imgv
6880 when Attribute_Width =>
6881 Exp_Imgv.Expand_Width_Attribute (N, Normal);
6887 when Attribute_Write => Write : declare
6888 P_Type : constant Entity_Id := Entity (Pref);
6889 U_Type : constant Entity_Id := Underlying_Type (P_Type);
6897 -- If no underlying type, we have an error that will be diagnosed
6898 -- elsewhere, so here we just completely ignore the expansion.
6904 -- Stream operations can appear in user code even if the restriction
6905 -- No_Streams is active (for example, when instantiating a predefined
6906 -- container). In that case rewrite the attribute as a Raise to
6907 -- prevent any run-time use.
6909 if Restriction_Active (No_Streams) then
6911 Make_Raise_Program_Error (Sloc (N),
6912 Reason => PE_Stream_Operation_Not_Allowed));
6913 Set_Etype (N, U_Type);
6917 -- The simple case, if there is a TSS for Write, just call it
6919 Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Write);
6921 if Present (Pname) then
6925 -- If there is a Stream_Convert pragma, use it, we rewrite
6927 -- sourcetyp'Output (stream, Item)
6931 -- strmtyp'Output (Stream, strmwrite (acttyp (Item)));
6933 -- where strmwrite is the given Write function that converts an
6934 -- argument of type sourcetyp or a type acctyp, from which it is
6935 -- derived to type strmtyp. The conversion to acttyp is required
6936 -- for the derived case.
6938 Prag := Get_Stream_Convert_Pragma (P_Type);
6940 if Present (Prag) then
6942 Next (Next (First (Pragma_Argument_Associations (Prag))));
6943 Wfunc := Entity (Expression (Arg3));
6946 Make_Attribute_Reference (Loc,
6947 Prefix => New_Occurrence_Of (Etype (Wfunc), Loc),
6948 Attribute_Name => Name_Output,
6949 Expressions => New_List (
6950 Relocate_Node (First (Exprs)),
6951 Make_Function_Call (Loc,
6952 Name => New_Occurrence_Of (Wfunc, Loc),
6953 Parameter_Associations => New_List (
6954 OK_Convert_To (Etype (First_Formal (Wfunc)),
6955 Relocate_Node (Next (First (Exprs)))))))));
6960 -- For elementary types, we call the W_xxx routine directly
6962 elsif Is_Elementary_Type (U_Type) then
6963 Rewrite (N, Build_Elementary_Write_Call (N));
6969 elsif Is_Array_Type (U_Type) then
6970 Build_Array_Write_Procedure (N, U_Type, Decl, Pname);
6971 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
6973 -- Tagged type case, use the primitive Write function. Note that
6974 -- this will dispatch in the class-wide case which is what we want
6976 elsif Is_Tagged_Type (U_Type) then
6977 Pname := Find_Prim_Op (U_Type, TSS_Stream_Write);
6979 -- All other record type cases, including protected records.
6980 -- The latter only arise for expander generated code for
6981 -- handling shared passive partition access.
6985 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
6987 -- Ada 2005 (AI-216): Program_Error is raised when executing
6988 -- the default implementation of the Write attribute of an
6989 -- Unchecked_Union type. However, if the 'Write reference is
6990 -- within the generated Output stream procedure, Write outputs
6991 -- the components, and the default values of the discriminant
6992 -- are streamed by the Output procedure itself.
6994 if Is_Unchecked_Union (Base_Type (U_Type))
6995 and not Is_TSS (Current_Scope, TSS_Stream_Output)
6998 Make_Raise_Program_Error (Loc,
6999 Reason => PE_Unchecked_Union_Restriction));
7002 if Has_Discriminants (U_Type)
7004 (Discriminant_Default_Value (First_Discriminant (U_Type)))
7006 Build_Mutable_Record_Write_Procedure
7007 (Loc, Full_Base (U_Type), Decl, Pname);
7009 Build_Record_Write_Procedure
7010 (Loc, Full_Base (U_Type), Decl, Pname);
7013 Insert_Action (N, Decl);
7017 -- If we fall through, Pname is the procedure to be called
7019 Rewrite_Stream_Proc_Call (Pname);
7022 -- Component_Size is handled by the back end, unless the component size
7023 -- is known at compile time, which is always true in the packed array
7024 -- case. It is important that the packed array case is handled in the
7025 -- front end (see Eval_Attribute) since the back end would otherwise get
7026 -- confused by the equivalent packed array type.
7028 when Attribute_Component_Size =>
7031 -- The following attributes are handled by the back end (except that
7032 -- static cases have already been evaluated during semantic processing,
7033 -- but in any case the back end should not count on this).
7035 -- The back end also handles the non-class-wide cases of Size
7037 when Attribute_Bit_Order |
7038 Attribute_Code_Address |
7039 Attribute_Definite |
7041 Attribute_Null_Parameter |
7042 Attribute_Passed_By_Reference |
7043 Attribute_Pool_Address |
7044 Attribute_Scalar_Storage_Order =>
7047 -- The following attributes are also handled by the back end, but return
7048 -- a universal integer result, so may need a conversion for checking
7049 -- that the result is in range.
7051 when Attribute_Aft |
7052 Attribute_Max_Alignment_For_Allocation =>
7053 Apply_Universal_Integer_Attribute_Checks (N);
7055 -- The following attributes should not appear at this stage, since they
7056 -- have already been handled by the analyzer (and properly rewritten
7057 -- with corresponding values or entities to represent the right values)
7059 when Attribute_Abort_Signal |
7060 Attribute_Address_Size |
7061 Attribute_Atomic_Always_Lock_Free |
7064 Attribute_Compiler_Version |
7065 Attribute_Default_Bit_Order |
7066 Attribute_Default_Scalar_Storage_Order |
7073 Attribute_Fast_Math |
7074 Attribute_First_Valid |
7075 Attribute_Has_Access_Values |
7076 Attribute_Has_Discriminants |
7077 Attribute_Has_Tagged_Values |
7079 Attribute_Last_Valid |
7080 Attribute_Library_Level |
7081 Attribute_Lock_Free |
7082 Attribute_Machine_Emax |
7083 Attribute_Machine_Emin |
7084 Attribute_Machine_Mantissa |
7085 Attribute_Machine_Overflows |
7086 Attribute_Machine_Radix |
7087 Attribute_Machine_Rounds |
7088 Attribute_Maximum_Alignment |
7089 Attribute_Model_Emin |
7090 Attribute_Model_Epsilon |
7091 Attribute_Model_Mantissa |
7092 Attribute_Model_Small |
7094 Attribute_Partition_ID |
7096 Attribute_Restriction_Set |
7097 Attribute_Safe_Emax |
7098 Attribute_Safe_First |
7099 Attribute_Safe_Large |
7100 Attribute_Safe_Last |
7101 Attribute_Safe_Small |
7103 Attribute_Signed_Zeros |
7105 Attribute_Storage_Unit |
7106 Attribute_Stub_Type |
7107 Attribute_System_Allocator_Alignment |
7108 Attribute_Target_Name |
7109 Attribute_Type_Class |
7110 Attribute_Type_Key |
7111 Attribute_Unconstrained_Array |
7112 Attribute_Universal_Literal_String |
7113 Attribute_Wchar_T_Size |
7114 Attribute_Word_Size =>
7115 raise Program_Error;
7117 -- The Asm_Input and Asm_Output attributes are not expanded at this
7118 -- stage, but will be eliminated in the expansion of the Asm call, see
7119 -- Exp_Intr for details. So the back end will never see these either.
7121 when Attribute_Asm_Input |
7122 Attribute_Asm_Output =>
7126 -- Note: as mentioned earlier, individual sections of the above case
7127 -- statement assume there is no code after the case statement, and are
7128 -- legitimately allowed to execute return statements if they have nothing
7129 -- more to do, so DO NOT add code at this point.
7132 when RE_Not_Available =>
7134 end Expand_N_Attribute_Reference;
7136 --------------------------------
7137 -- Expand_Pred_Succ_Attribute --
7138 --------------------------------
7140 -- For typ'Pred (exp), we generate the check
7142 -- [constraint_error when exp = typ'Base'First]
7144 -- Similarly, for typ'Succ (exp), we generate the check
7146 -- [constraint_error when exp = typ'Base'Last]
7148 -- These checks are not generated for modular types, since the proper
7149 -- semantics for Succ and Pred on modular types is to wrap, not raise CE.
7150 -- We also suppress these checks if we are the right side of an assignment
7151 -- statement or the expression of an object declaration, where the flag
7152 -- Suppress_Assignment_Checks is set for the assignment/declaration.
7154 procedure Expand_Pred_Succ_Attribute (N : Node_Id) is
7155 Loc : constant Source_Ptr := Sloc (N);
7156 P : constant Node_Id := Parent (N);
7160 if Attribute_Name (N) = Name_Pred then
7166 if not Nkind_In (P, N_Assignment_Statement, N_Object_Declaration)
7167 or else not Suppress_Assignment_Checks (P)
7170 Make_Raise_Constraint_Error (Loc,
7174 Duplicate_Subexpr_Move_Checks (First (Expressions (N))),
7176 Make_Attribute_Reference (Loc,
7178 New_Occurrence_Of (Base_Type (Etype (Prefix (N))), Loc),
7179 Attribute_Name => Cnam)),
7180 Reason => CE_Overflow_Check_Failed));
7182 end Expand_Pred_Succ_Attribute;
7184 -----------------------------
7185 -- Expand_Update_Attribute --
7186 -----------------------------
7188 procedure Expand_Update_Attribute (N : Node_Id) is
7189 procedure Process_Component_Or_Element_Update
7194 -- Generate the statements necessary to update a single component or an
7195 -- element of the prefix. The code is inserted before the attribute N.
7196 -- Temp denotes the entity of the anonymous object created to reflect
7197 -- the changes in values. Comp is the component/index expression to be
7198 -- updated. Expr is an expression yielding the new value of Comp. Typ
7199 -- is the type of the prefix of attribute Update.
7201 procedure Process_Range_Update
7206 -- Generate the statements necessary to update a slice of the prefix.
7207 -- The code is inserted before the attribute N. Temp denotes the entity
7208 -- of the anonymous object created to reflect the changes in values.
7209 -- Comp is range of the slice to be updated. Expr is an expression
7210 -- yielding the new value of Comp. Typ is the type of the prefix of
7211 -- attribute Update.
7213 -----------------------------------------
7214 -- Process_Component_Or_Element_Update --
7215 -----------------------------------------
7217 procedure Process_Component_Or_Element_Update
7223 Loc : constant Source_Ptr := Sloc (Comp);
7228 -- An array element may be modified by the following relations
7229 -- depending on the number of dimensions:
7231 -- 1 => Expr -- one dimensional update
7232 -- (1, ..., N) => Expr -- multi dimensional update
7234 -- The above forms are converted in assignment statements where the
7235 -- left hand side is an indexed component:
7237 -- Temp (1) := Expr; -- one dimensional update
7238 -- Temp (1, ..., N) := Expr; -- multi dimensional update
7240 if Is_Array_Type (Typ) then
7242 -- The index expressions of a multi dimensional array update
7243 -- appear as an aggregate.
7245 if Nkind (Comp) = N_Aggregate then
7246 Exprs := New_Copy_List_Tree (Expressions (Comp));
7248 Exprs := New_List (Relocate_Node (Comp));
7252 Make_Indexed_Component (Loc,
7253 Prefix => New_Occurrence_Of (Temp, Loc),
7254 Expressions => Exprs);
7256 -- A record component update appears in the following form:
7260 -- The above relation is transformed into an assignment statement
7261 -- where the left hand side is a selected component:
7263 -- Temp.Comp := Expr;
7265 else pragma Assert (Is_Record_Type (Typ));
7267 Make_Selected_Component (Loc,
7268 Prefix => New_Occurrence_Of (Temp, Loc),
7269 Selector_Name => Relocate_Node (Comp));
7273 Make_Assignment_Statement (Loc,
7275 Expression => Relocate_Node (Expr)));
7276 end Process_Component_Or_Element_Update;
7278 --------------------------
7279 -- Process_Range_Update --
7280 --------------------------
7282 procedure Process_Range_Update
7288 Index_Typ : constant Entity_Id := Etype (First_Index (Typ));
7289 Loc : constant Source_Ptr := Sloc (Comp);
7293 -- A range update appears as
7295 -- (Low .. High => Expr)
7297 -- The above construct is transformed into a loop that iterates over
7298 -- the given range and modifies the corresponding array values to the
7301 -- for Index in Low .. High loop
7302 -- Temp (<Index_Typ> (Index)) := Expr;
7305 Index := Make_Temporary (Loc, 'I');
7308 Make_Loop_Statement (Loc,
7310 Make_Iteration_Scheme (Loc,
7311 Loop_Parameter_Specification =>
7312 Make_Loop_Parameter_Specification (Loc,
7313 Defining_Identifier => Index,
7314 Discrete_Subtype_Definition => Relocate_Node (Comp))),
7316 Statements => New_List (
7317 Make_Assignment_Statement (Loc,
7319 Make_Indexed_Component (Loc,
7320 Prefix => New_Occurrence_Of (Temp, Loc),
7321 Expressions => New_List (
7322 Convert_To (Index_Typ,
7323 New_Occurrence_Of (Index, Loc)))),
7324 Expression => Relocate_Node (Expr))),
7326 End_Label => Empty));
7327 end Process_Range_Update;
7331 Aggr : constant Node_Id := First (Expressions (N));
7332 Loc : constant Source_Ptr := Sloc (N);
7333 Pref : constant Node_Id := Prefix (N);
7334 Typ : constant Entity_Id := Etype (Pref);
7337 CW_Temp : Entity_Id;
7342 -- Start of processing for Expand_Update_Attribute
7345 -- Create the anonymous object to store the value of the prefix and
7346 -- capture subsequent changes in value.
7348 Temp := Make_Temporary (Loc, 'T', Pref);
7350 -- Preserve the tag of the prefix by offering a specific view of the
7351 -- class-wide version of the prefix.
7353 if Is_Tagged_Type (Typ) then
7356 -- CW_Temp : Typ'Class := Typ'Class (Pref);
7358 CW_Temp := Make_Temporary (Loc, 'T');
7359 CW_Typ := Class_Wide_Type (Typ);
7362 Make_Object_Declaration (Loc,
7363 Defining_Identifier => CW_Temp,
7364 Object_Definition => New_Occurrence_Of (CW_Typ, Loc),
7366 Convert_To (CW_Typ, Relocate_Node (Pref))));
7369 -- Temp : Typ renames Typ (CW_Temp);
7372 Make_Object_Renaming_Declaration (Loc,
7373 Defining_Identifier => Temp,
7374 Subtype_Mark => New_Occurrence_Of (Typ, Loc),
7376 Convert_To (Typ, New_Occurrence_Of (CW_Temp, Loc))));
7382 -- Temp : Typ := Pref;
7385 Make_Object_Declaration (Loc,
7386 Defining_Identifier => Temp,
7387 Object_Definition => New_Occurrence_Of (Typ, Loc),
7388 Expression => Relocate_Node (Pref)));
7391 -- Process the update aggregate
7393 Assoc := First (Component_Associations (Aggr));
7394 while Present (Assoc) loop
7395 Comp := First (Choices (Assoc));
7396 Expr := Expression (Assoc);
7397 while Present (Comp) loop
7398 if Nkind (Comp) = N_Range then
7399 Process_Range_Update (Temp, Comp, Expr, Typ);
7401 Process_Component_Or_Element_Update (Temp, Comp, Expr, Typ);
7410 -- The attribute is replaced by a reference to the anonymous object
7412 Rewrite (N, New_Occurrence_Of (Temp, Loc));
7414 end Expand_Update_Attribute;
7420 procedure Find_Fat_Info
7422 Fat_Type : out Entity_Id;
7423 Fat_Pkg : out RE_Id)
7425 Rtyp : constant Entity_Id := Root_Type (T);
7428 -- All we do is use the root type (historically this dealt with
7429 -- VAX-float .. to be cleaned up further later ???)
7433 if Fat_Type = Standard_Short_Float then
7434 Fat_Pkg := RE_Attr_Short_Float;
7436 elsif Fat_Type = Standard_Float then
7437 Fat_Pkg := RE_Attr_Float;
7439 elsif Fat_Type = Standard_Long_Float then
7440 Fat_Pkg := RE_Attr_Long_Float;
7442 elsif Fat_Type = Standard_Long_Long_Float then
7443 Fat_Pkg := RE_Attr_Long_Long_Float;
7445 -- Universal real (which is its own root type) is treated as being
7446 -- equivalent to Standard.Long_Long_Float, since it is defined to
7447 -- have the same precision as the longest Float type.
7449 elsif Fat_Type = Universal_Real then
7450 Fat_Type := Standard_Long_Long_Float;
7451 Fat_Pkg := RE_Attr_Long_Long_Float;
7454 raise Program_Error;
7458 ----------------------------
7459 -- Find_Stream_Subprogram --
7460 ----------------------------
7462 function Find_Stream_Subprogram
7464 Nam : TSS_Name_Type) return Entity_Id
7466 Base_Typ : constant Entity_Id := Base_Type (Typ);
7467 Ent : constant Entity_Id := TSS (Typ, Nam);
7469 function Is_Available (Entity : RE_Id) return Boolean;
7470 pragma Inline (Is_Available);
7471 -- Function to check whether the specified run-time call is available
7472 -- in the run time used. In the case of a configurable run time, it
7473 -- is normal that some subprograms are not there.
7475 -- I don't understand this routine at all, why is this not just a
7476 -- call to RTE_Available? And if for some reason we need a different
7477 -- routine with different semantics, why is not in Rtsfind ???
7483 function Is_Available (Entity : RE_Id) return Boolean is
7485 -- Assume that the unit will always be available when using a
7486 -- "normal" (not configurable) run time.
7488 return not Configurable_Run_Time_Mode or else RTE_Available (Entity);
7491 -- Start of processing for Find_Stream_Subprogram
7494 if Present (Ent) then
7498 -- Stream attributes for strings are expanded into library calls. The
7499 -- following checks are disabled when the run-time is not available or
7500 -- when compiling predefined types due to bootstrap issues. As a result,
7501 -- the compiler will generate in-place stream routines for string types
7502 -- that appear in GNAT's library, but will generate calls via rtsfind
7503 -- to library routines for user code.
7505 -- This is disabled for AAMP, to avoid creating dependences on files not
7506 -- supported in the AAMP library (such as s-fileio.adb).
7508 -- Note: In the case of using a configurable run time, it is very likely
7509 -- that stream routines for string types are not present (they require
7510 -- file system support). In this case, the specific stream routines for
7511 -- strings are not used, relying on the regular stream mechanism
7512 -- instead. That is why we include the test Is_Available when dealing
7513 -- with these cases.
7515 if not AAMP_On_Target
7517 not Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
7519 -- Storage_Array as defined in package System.Storage_Elements
7521 if Is_RTE (Base_Typ, RE_Storage_Array) then
7523 -- Case of No_Stream_Optimizations restriction active
7525 if Restriction_Active (No_Stream_Optimizations) then
7526 if Nam = TSS_Stream_Input
7527 and then Is_Available (RE_Storage_Array_Input)
7529 return RTE (RE_Storage_Array_Input);
7531 elsif Nam = TSS_Stream_Output
7532 and then Is_Available (RE_Storage_Array_Output)
7534 return RTE (RE_Storage_Array_Output);
7536 elsif Nam = TSS_Stream_Read
7537 and then Is_Available (RE_Storage_Array_Read)
7539 return RTE (RE_Storage_Array_Read);
7541 elsif Nam = TSS_Stream_Write
7542 and then Is_Available (RE_Storage_Array_Write)
7544 return RTE (RE_Storage_Array_Write);
7546 elsif Nam /= TSS_Stream_Input and then
7547 Nam /= TSS_Stream_Output and then
7548 Nam /= TSS_Stream_Read and then
7549 Nam /= TSS_Stream_Write
7551 raise Program_Error;
7554 -- Restriction No_Stream_Optimizations is not set, so we can go
7555 -- ahead and optimize using the block IO forms of the routines.
7558 if Nam = TSS_Stream_Input
7559 and then Is_Available (RE_Storage_Array_Input_Blk_IO)
7561 return RTE (RE_Storage_Array_Input_Blk_IO);
7563 elsif Nam = TSS_Stream_Output
7564 and then Is_Available (RE_Storage_Array_Output_Blk_IO)
7566 return RTE (RE_Storage_Array_Output_Blk_IO);
7568 elsif Nam = TSS_Stream_Read
7569 and then Is_Available (RE_Storage_Array_Read_Blk_IO)
7571 return RTE (RE_Storage_Array_Read_Blk_IO);
7573 elsif Nam = TSS_Stream_Write
7574 and then Is_Available (RE_Storage_Array_Write_Blk_IO)
7576 return RTE (RE_Storage_Array_Write_Blk_IO);
7578 elsif Nam /= TSS_Stream_Input and then
7579 Nam /= TSS_Stream_Output and then
7580 Nam /= TSS_Stream_Read and then
7581 Nam /= TSS_Stream_Write
7583 raise Program_Error;
7587 -- Stream_Element_Array as defined in package Ada.Streams
7589 elsif Is_RTE (Base_Typ, RE_Stream_Element_Array) then
7591 -- Case of No_Stream_Optimizations restriction active
7593 if Restriction_Active (No_Stream_Optimizations) then
7594 if Nam = TSS_Stream_Input
7595 and then Is_Available (RE_Stream_Element_Array_Input)
7597 return RTE (RE_Stream_Element_Array_Input);
7599 elsif Nam = TSS_Stream_Output
7600 and then Is_Available (RE_Stream_Element_Array_Output)
7602 return RTE (RE_Stream_Element_Array_Output);
7604 elsif Nam = TSS_Stream_Read
7605 and then Is_Available (RE_Stream_Element_Array_Read)
7607 return RTE (RE_Stream_Element_Array_Read);
7609 elsif Nam = TSS_Stream_Write
7610 and then Is_Available (RE_Stream_Element_Array_Write)
7612 return RTE (RE_Stream_Element_Array_Write);
7614 elsif Nam /= TSS_Stream_Input and then
7615 Nam /= TSS_Stream_Output and then
7616 Nam /= TSS_Stream_Read and then
7617 Nam /= TSS_Stream_Write
7619 raise Program_Error;
7622 -- Restriction No_Stream_Optimizations is not set, so we can go
7623 -- ahead and optimize using the block IO forms of the routines.
7626 if Nam = TSS_Stream_Input
7627 and then Is_Available (RE_Stream_Element_Array_Input_Blk_IO)
7629 return RTE (RE_Stream_Element_Array_Input_Blk_IO);
7631 elsif Nam = TSS_Stream_Output
7632 and then Is_Available (RE_Stream_Element_Array_Output_Blk_IO)
7634 return RTE (RE_Stream_Element_Array_Output_Blk_IO);
7636 elsif Nam = TSS_Stream_Read
7637 and then Is_Available (RE_Stream_Element_Array_Read_Blk_IO)
7639 return RTE (RE_Stream_Element_Array_Read_Blk_IO);
7641 elsif Nam = TSS_Stream_Write
7642 and then Is_Available (RE_Stream_Element_Array_Write_Blk_IO)
7644 return RTE (RE_Stream_Element_Array_Write_Blk_IO);
7646 elsif Nam /= TSS_Stream_Input and then
7647 Nam /= TSS_Stream_Output and then
7648 Nam /= TSS_Stream_Read and then
7649 Nam /= TSS_Stream_Write
7651 raise Program_Error;
7655 -- String as defined in package Ada
7657 elsif Base_Typ = Standard_String then
7659 -- Case of No_Stream_Optimizations restriction active
7661 if Restriction_Active (No_Stream_Optimizations) then
7662 if Nam = TSS_Stream_Input
7663 and then Is_Available (RE_String_Input)
7665 return RTE (RE_String_Input);
7667 elsif Nam = TSS_Stream_Output
7668 and then Is_Available (RE_String_Output)
7670 return RTE (RE_String_Output);
7672 elsif Nam = TSS_Stream_Read
7673 and then Is_Available (RE_String_Read)
7675 return RTE (RE_String_Read);
7677 elsif Nam = TSS_Stream_Write
7678 and then Is_Available (RE_String_Write)
7680 return RTE (RE_String_Write);
7682 elsif Nam /= TSS_Stream_Input and then
7683 Nam /= TSS_Stream_Output and then
7684 Nam /= TSS_Stream_Read and then
7685 Nam /= TSS_Stream_Write
7687 raise Program_Error;
7690 -- Restriction No_Stream_Optimizations is not set, so we can go
7691 -- ahead and optimize using the block IO forms of the routines.
7694 if Nam = TSS_Stream_Input
7695 and then Is_Available (RE_String_Input_Blk_IO)
7697 return RTE (RE_String_Input_Blk_IO);
7699 elsif Nam = TSS_Stream_Output
7700 and then Is_Available (RE_String_Output_Blk_IO)
7702 return RTE (RE_String_Output_Blk_IO);
7704 elsif Nam = TSS_Stream_Read
7705 and then Is_Available (RE_String_Read_Blk_IO)
7707 return RTE (RE_String_Read_Blk_IO);
7709 elsif Nam = TSS_Stream_Write
7710 and then Is_Available (RE_String_Write_Blk_IO)
7712 return RTE (RE_String_Write_Blk_IO);
7714 elsif Nam /= TSS_Stream_Input and then
7715 Nam /= TSS_Stream_Output and then
7716 Nam /= TSS_Stream_Read and then
7717 Nam /= TSS_Stream_Write
7719 raise Program_Error;
7723 -- Wide_String as defined in package Ada
7725 elsif Base_Typ = Standard_Wide_String then
7727 -- Case of No_Stream_Optimizations restriction active
7729 if Restriction_Active (No_Stream_Optimizations) then
7730 if Nam = TSS_Stream_Input
7731 and then Is_Available (RE_Wide_String_Input)
7733 return RTE (RE_Wide_String_Input);
7735 elsif Nam = TSS_Stream_Output
7736 and then Is_Available (RE_Wide_String_Output)
7738 return RTE (RE_Wide_String_Output);
7740 elsif Nam = TSS_Stream_Read
7741 and then Is_Available (RE_Wide_String_Read)
7743 return RTE (RE_Wide_String_Read);
7745 elsif Nam = TSS_Stream_Write
7746 and then Is_Available (RE_Wide_String_Write)
7748 return RTE (RE_Wide_String_Write);
7750 elsif Nam /= TSS_Stream_Input and then
7751 Nam /= TSS_Stream_Output and then
7752 Nam /= TSS_Stream_Read and then
7753 Nam /= TSS_Stream_Write
7755 raise Program_Error;
7758 -- Restriction No_Stream_Optimizations is not set, so we can go
7759 -- ahead and optimize using the block IO forms of the routines.
7762 if Nam = TSS_Stream_Input
7763 and then Is_Available (RE_Wide_String_Input_Blk_IO)
7765 return RTE (RE_Wide_String_Input_Blk_IO);
7767 elsif Nam = TSS_Stream_Output
7768 and then Is_Available (RE_Wide_String_Output_Blk_IO)
7770 return RTE (RE_Wide_String_Output_Blk_IO);
7772 elsif Nam = TSS_Stream_Read
7773 and then Is_Available (RE_Wide_String_Read_Blk_IO)
7775 return RTE (RE_Wide_String_Read_Blk_IO);
7777 elsif Nam = TSS_Stream_Write
7778 and then Is_Available (RE_Wide_String_Write_Blk_IO)
7780 return RTE (RE_Wide_String_Write_Blk_IO);
7782 elsif Nam /= TSS_Stream_Input and then
7783 Nam /= TSS_Stream_Output and then
7784 Nam /= TSS_Stream_Read and then
7785 Nam /= TSS_Stream_Write
7787 raise Program_Error;
7791 -- Wide_Wide_String as defined in package Ada
7793 elsif Base_Typ = Standard_Wide_Wide_String then
7795 -- Case of No_Stream_Optimizations restriction active
7797 if Restriction_Active (No_Stream_Optimizations) then
7798 if Nam = TSS_Stream_Input
7799 and then Is_Available (RE_Wide_Wide_String_Input)
7801 return RTE (RE_Wide_Wide_String_Input);
7803 elsif Nam = TSS_Stream_Output
7804 and then Is_Available (RE_Wide_Wide_String_Output)
7806 return RTE (RE_Wide_Wide_String_Output);
7808 elsif Nam = TSS_Stream_Read
7809 and then Is_Available (RE_Wide_Wide_String_Read)
7811 return RTE (RE_Wide_Wide_String_Read);
7813 elsif Nam = TSS_Stream_Write
7814 and then Is_Available (RE_Wide_Wide_String_Write)
7816 return RTE (RE_Wide_Wide_String_Write);
7818 elsif Nam /= TSS_Stream_Input and then
7819 Nam /= TSS_Stream_Output and then
7820 Nam /= TSS_Stream_Read and then
7821 Nam /= TSS_Stream_Write
7823 raise Program_Error;
7826 -- Restriction No_Stream_Optimizations is not set, so we can go
7827 -- ahead and optimize using the block IO forms of the routines.
7830 if Nam = TSS_Stream_Input
7831 and then Is_Available (RE_Wide_Wide_String_Input_Blk_IO)
7833 return RTE (RE_Wide_Wide_String_Input_Blk_IO);
7835 elsif Nam = TSS_Stream_Output
7836 and then Is_Available (RE_Wide_Wide_String_Output_Blk_IO)
7838 return RTE (RE_Wide_Wide_String_Output_Blk_IO);
7840 elsif Nam = TSS_Stream_Read
7841 and then Is_Available (RE_Wide_Wide_String_Read_Blk_IO)
7843 return RTE (RE_Wide_Wide_String_Read_Blk_IO);
7845 elsif Nam = TSS_Stream_Write
7846 and then Is_Available (RE_Wide_Wide_String_Write_Blk_IO)
7848 return RTE (RE_Wide_Wide_String_Write_Blk_IO);
7850 elsif Nam /= TSS_Stream_Input and then
7851 Nam /= TSS_Stream_Output and then
7852 Nam /= TSS_Stream_Read and then
7853 Nam /= TSS_Stream_Write
7855 raise Program_Error;
7861 if Is_Tagged_Type (Typ) and then Is_Derived_Type (Typ) then
7862 return Find_Prim_Op (Typ, Nam);
7864 return Find_Inherited_TSS (Typ, Nam);
7866 end Find_Stream_Subprogram;
7872 function Full_Base (T : Entity_Id) return Entity_Id is
7876 BT := Base_Type (T);
7878 if Is_Private_Type (BT)
7879 and then Present (Full_View (BT))
7881 BT := Full_View (BT);
7887 -----------------------
7888 -- Get_Index_Subtype --
7889 -----------------------
7891 function Get_Index_Subtype (N : Node_Id) return Node_Id is
7892 P_Type : Entity_Id := Etype (Prefix (N));
7897 if Is_Access_Type (P_Type) then
7898 P_Type := Designated_Type (P_Type);
7901 if No (Expressions (N)) then
7904 J := UI_To_Int (Expr_Value (First (Expressions (N))));
7907 Indx := First_Index (P_Type);
7913 return Etype (Indx);
7914 end Get_Index_Subtype;
7916 -------------------------------
7917 -- Get_Stream_Convert_Pragma --
7918 -------------------------------
7920 function Get_Stream_Convert_Pragma (T : Entity_Id) return Node_Id is
7925 -- Note: we cannot use Get_Rep_Pragma here because of the peculiarity
7926 -- that a stream convert pragma for a tagged type is not inherited from
7927 -- its parent. Probably what is wrong here is that it is basically
7928 -- incorrect to consider a stream convert pragma to be a representation
7929 -- pragma at all ???
7931 N := First_Rep_Item (Implementation_Base_Type (T));
7932 while Present (N) loop
7933 if Nkind (N) = N_Pragma
7934 and then Pragma_Name (N) = Name_Stream_Convert
7936 -- For tagged types this pragma is not inherited, so we
7937 -- must verify that it is defined for the given type and
7941 Entity (Expression (First (Pragma_Argument_Associations (N))));
7943 if not Is_Tagged_Type (T)
7945 or else (Is_Private_Type (Typ) and then T = Full_View (Typ))
7955 end Get_Stream_Convert_Pragma;
7957 ---------------------------------
7958 -- Is_Constrained_Packed_Array --
7959 ---------------------------------
7961 function Is_Constrained_Packed_Array (Typ : Entity_Id) return Boolean is
7962 Arr : Entity_Id := Typ;
7965 if Is_Access_Type (Arr) then
7966 Arr := Designated_Type (Arr);
7969 return Is_Array_Type (Arr)
7970 and then Is_Constrained (Arr)
7971 and then Present (Packed_Array_Impl_Type (Arr));
7972 end Is_Constrained_Packed_Array;
7974 ----------------------------------------
7975 -- Is_Inline_Floating_Point_Attribute --
7976 ----------------------------------------
7978 function Is_Inline_Floating_Point_Attribute (N : Node_Id) return Boolean is
7979 Id : constant Attribute_Id := Get_Attribute_Id (Attribute_Name (N));
7981 function Is_GCC_Target return Boolean;
7982 -- Return True if we are using a GCC target/back-end
7983 -- ??? Note: the implementation is kludgy/fragile
7989 function Is_GCC_Target return Boolean is
7991 return not CodePeer_Mode
7992 and then not AAMP_On_Target
7993 and then not Generate_C_Code;
7996 -- Start of processing for Exp_Attr
7999 -- Machine and Model can be expanded by the GCC backend only
8001 if Id = Attribute_Machine or else Id = Attribute_Model then
8002 return Is_GCC_Target;
8004 -- Remaining cases handled by all back ends are Rounding and Truncation
8005 -- when appearing as the operand of a conversion to some integer type.
8007 elsif Nkind (Parent (N)) /= N_Type_Conversion
8008 or else not Is_Integer_Type (Etype (Parent (N)))
8013 -- Here we are in the integer conversion context
8015 -- Very probably we should also recognize the cases of Machine_Rounding
8016 -- and unbiased rounding in this conversion context, but the back end is
8017 -- not yet prepared to handle these cases ???
8019 return Id = Attribute_Rounding or else Id = Attribute_Truncation;
8020 end Is_Inline_Floating_Point_Attribute;